chore: update v1.0.0 release date, remove old gitpod-related stuff

.gitpod.yml

@@ -1,14 +0,0 @@
-github:
-  prebuilds:
-    pullRequestsFromForks: true
-
-vscode:
-  extensions:
-    - ms-vscode.makefile-tools
-    - james-yu.latex-workshop
-    - editorconfig.editorconfig
-
-tasks:
-  - before: sudo apt update && sudo apt install -y texlive texlive-latex-extra
-  - before: pip install -U pip poetry
-    init: poetry install

CHANGELOG.md

@@ -1,4 +1,4 @@
-# [Version 1.0.0](https://github.com/Kosmorro/kosmorro/compare/v0.10.13...v1.0.0) (2025-12-12)
+# [Version 1.0.0](https://github.com/Kosmorro/kosmorro/compare/v0.10.13...v1.0.0) (2026-01-03)
 
 ### Features
 

CONTRIBUTING.md

@@ -21,8 +21,6 @@ If you speak another language than English, another nice way to enhance Kosmorro
 
 ## Writing code
 
-[![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/Kosmorro/kosmorro)
-
 First, 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 (`Kosmorro/kosmorro`), so you can update your fork with the last upstream commits.