docs: add docs and license

CONTRIBUTING.md

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+# Contributing to Kosmorro
+
+If you are reading this, then you are probably looking for a way to contribute to Kosmorro (you're in the good place!). Thank you!
+There are multiple ways to contribute that can match with your possibilities.
+
+## Opening issues
+
+### Reporting bugs
+
+If you found a bug, please check it is not already reported in the _Issues_ tab.
+If it is not, [create a bug report](https://github.com/Kosmorro/lib/issues/new/choose) and fill in the template that offers to you. Feel free to give as much information as possible, as it will make the bug easier to fix.
+
+### Suggest a new feature
+
+Have an idea of feature you think would be nice on Kosmorro? Time to suggest it!
+First, please check someone didn't suggest your next revolution in the _Issues_ tab. If it's not, [create a feature request](https://github.com/Deuchnord/kosmorro/issues/new/choose) and fill in the templace that offers to you.
+
+## Writing code
+
+First of all, if you are fixing an opened issue, check that nobody is already working on it — if someone seems to be but their Pull Request seems stuck, please ask them first if you can continue the development. If you retake the code they produced, **don't change the author of the commits**.
+
+Before writing the code, first create a fork of the repository and clone it. You may also want to add the original repository (`Deuchnord/kosmorro`), so you can update your fork with the last upstream commits.
+
+Then create a new branch and start coding. Finally, commit and push, then open a PR on this project. If your project is not complete, feel free to open it as Draft (if you forgot to activate the Draft status, just edit the first comment to say it), then mark it as ready for review when you're done.
+
+### Choosing the right target branch
+
+Whatever you are doing, always base your working branch on `master`.
+When you create your PR, please consider selecting the right target branch:
+
+- If you are fixing a bug or optimizing something, then target the `master` branch.
+- If you are doing anything else, then target the `feature` branch.
+
+This allows to make easier to publish patch releases, which have a higher priority than the minor releases.
+
+### Matching the coding standards
+
+Kosmorro's source code follows the major coding standards of Python (PEPs). Before marking your Pull Request as ready for review, don't forget to check that the code respects the coding standards with PyLint (it is run on the CI, but feel free to run it on your local machine too). Your PR must have a global note of 10/10 to be elligible to merge.
+To ensure your code is matching the coding standards, you can use [`black`](https://github.com/psf/black) to fix the potential issues.
+
+### Testing the code
+
+[Unit tests](https://en.wikipedia.org/wiki/Unit_testing) check that every little piece of code (any _unit_) does exactly what it is supposed to do. They have several advantages, like proving that new things in the codebase works exactly as they should, and making sure that future changes done later won't break them.
+
+There are two kinds of tests on this project:
+
+- **legacy unit tests**, written with the `unittest` module
+- **Documentation tests** (Doctest), written directly in the docs of the library.
+
+The legacy tests are present for historic reason. If you want to add new tests, prefer the Doctest.
+
+To run the tests, invoke the following commands, depending on what you want to test:
+
+| Type | Command
+| --- | ---
+| Legacy tests | `make test`
+| Doctest | `python3 tests.py`
+
+Note: there are currently some memory leaks in the unit tests, making the result quite difficult to read. I am working to fix this.
+If you have troubles reading them, feel free to ask.
+
+### Commiting
+
+The commit messages of this project follow the [Conventional Commits Specification](https://www.conventionalcommits.org/en/v1.0.0/): basically, when you commit your changes, please prefix them with the following:
+
+- **`fix: `** if your changes fix a bug;
+- **`feat: `** if your changes add a new feature.
+
+The message of your commit must start with a lowercase.
+Finally, if your change introduce a BC-break, add a footer beginning with `BREAKING CHANGE:` and explaining precisely the BC-break.
+
+Once your PR is ready to review, please squash your commits so it contains only one commit.
+
+> To ensure your commits follow this convention, you can use [glint](https://github.com/brigand/glint).
+
+The commit messages are then used to generate the changelog using [`conventional-changelog`](https://github.com/conventional-changelog/conventional-changelog):
+
+```bash
+conventional-changelog -p angular -i CHANGELOG.md -s
+```
+
+## Licensing and Copyright Attribution
+
+When you open a Pull Request to the project, you agree to license your code under the [GNU Affero General Public License version 3](https://www.gnu.org/licenses/agpl-3.0.html).

LICENSE

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+
+
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+10.1 In the event of a breach by the Licensee of its obligations
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+
+
+    Article 11 - MISCELLANEOUS
+
+
+      11.1 EXCUSABLE EVENTS
+
+Neither Party shall be liable for any or all delay, or failure to
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+
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+
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+
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+conflict with a current or future applicable act or legislative text,
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+cause the Agreement as a whole to be invalid.
+
+
+      11.5 LANGUAGE
+
+The Agreement is drafted in both French and English and both versions
+are deemed authentic.
+
+
+    Article 12 - NEW VERSIONS OF THE AGREEMENT
+
+12.1 Any person is authorized to duplicate and distribute copies of this
+Agreement.
+
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+
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+
+
+    Article 13 - GOVERNING LAW AND JURISDICTION
+
+13.1 The Agreement is governed by French law. The Parties agree to
+endeavor to seek an amicable solution to any disagreements or disputes
+that may arise during the performance of the Agreement.
+
+13.2 Failing an amicable solution within two (2) months as from their
+occurrence, and unless emergency proceedings are necessary, the
+disagreements or disputes shall be referred to the Paris Courts having
+jurisdiction, by the more diligent Party.
+
+
+Version 1.0 dated 2006-09-05.

README.md

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+# Kosmorrolib - a library to compute your ephemerides!
+[![Coverage Status](https://coveralls.io/repos/github/Deuchnord/kosmorro/badge.svg)](https://coveralls.io/github/Deuchnord/kosmorro) [![Version on PyPI](https://img.shields.io/pypi/v/kosmorro)](https://pypi.org/project/kosmorro) [![Discord](https://img.shields.io/discord/650237632533757965?logo=discord&label=%23kosmorro)](https://discord.gg/nyemBqE)
+
+## Installation
+
+### Requirements
+
+Kosmorro requires the following software to work:
+
+- Python ≥ 3.5.0
+- PIP
+
+### Production environment
+
+Keep in mind that Kosmorro is still in alpha development stage and is not considered as stable.
+
+#### Linux
+
+##### Arch Linux, Manjaro…
+
+Kosmorro is available [in the AUR](https://aur.archlinux.org/packages/kosmorro).
+
+##### Other distributions
+
+Kosmorro is available [on PyPI](https://pypi.org/project/kosmorro/), a repository dedicated to Python.
+First, install `python-pip` on your system and invoke the following command: `pip install kosmorro`.
+
+#### macOS
+
+Currently, macOS does not provide Python 3, so you will first have to install it.
+If you don't have it, first install [HomeBrew](https://formulae.brew.sh), then install Python 3: `brew install python`.
+
+This will install Python 3 and its PIP on your system. Note that their executables are called `python3` and `pip3`.
+Now, you can install Kosmorro with your PIP: `pip3 install kosmorro`.
+
+#### Windows
+
+Kosmorro being at an early-stage development, Windows is not supported officially for now.
+
+### Development environment
+
+First, install [Pipenv](https://pypi.org/project/pipenv/).
+
+Clone this repository and run `pipenv sync` to install all the dependencies.
+Then, run Kosmorro by invoking `pipenv run python kosmorro`.
+
+For comfort, you may want to invoke `pipenv shell` first and then just `python kosmoro`.
+
+## Using Kosmorro
+
+Using Kosmorro is as simple as invoking `kosmorro` in your terminal!
+
+By default, it will give you the current Moon phase and, if any, the events that will occur today.
+To get the rise, culmination and set of the objects of the Solar system, you will need to give it your position on Earth: get your current coordinates (with [OpenStreetMap](https://www.openstreetmap.org) for instance), and give them to Kosmorro by invoking it with the following parameters: `--latitude=X --longitude=Y` (replace `X` by the latitude and `Y` by the longitude).
+
+Kosmorro has a lot of available options. To get a list of them, run `kosmorro --help`, or read its manual with `man kosmorro`.
+
+Note: the first time it runs, Kosmorro will download some important files needed to make the computations. They are stored in a cache folder named `.kosmorro-cache` located in your home directory (`/home/<username>` on Linux, `/Users/<username>` on macOS).
+
+### Exporting to PDF
+
+Kosmorro can export the computation results to PDF files, but this feature requires first that you install some additional dependencies. Before you use this feature, please check these packages are installed:
+
+- **A LaTeX distribution:**
+    - Linux: install TeXLive through your packages manager. Kosmorro just needs the minimal installation, you don't need any extension.
+    - macOS: install [MacTeX](https://www.tug.org/mactex/), the basic version will suffice:
+        - from the official website, choose the _smaller download_
+        - with Brew: `brew install basictex`
+- **The `latex` Python library:**
+    - Arch Linux: the library is available [on the AUR](https://aur.archlinux.org/packages/python-latex)
+    - Any other systems: install it through PyPI: `pip install latex`
+
+These dependencies are not installed by default, because they take a lot of place and are not necessary if you are not interested in generating PDF files.
+The first time you ask Kosmorro to create a PDF, it may be a little verbose. You can ignore its blahblah.
+
+### Opening the GUI
+
+![Screenshot](.github/assets/gui-screenshot.png)
+
+Kosmorro provides a graphical user interface that can be easily launched by invoking the `kosmorro --gui` command.
+
+To run it, you will have to install the `wxpython` package:
+
+- **On Linux**, wxPython is most likely provided by your packages manager.
+- **On Mac**, install wxPython by invoking `pip3 install wxPython`.
+
+  Alternatively, you may download the DMG file on the release page (note that you won't be able to use the command
+  line in this case).