Add Markdown plugin

Makefile

@@ -3,3 +3,7 @@ install:
 
 coc:
 	bash scripts/activate-coc
+
+markdown:
+	bash scripts/activate-markdown
+

README.md

@@ -16,3 +16,4 @@ The following plugins are installed with [Vundle](https://github.com/VundleVim/V
 | ------ | ----------- | ----------
 | [w0rp/ale](https://github.com/w0rp/ale) | Asynchronous linting/fixing for Vim and Language Server Protocol (LSP) integration | _Immediate_
 | [neoclide/coc.vim](https://github.com/neoclide/coc.nvim) | Intellisense engine for Vim 8 & neovim | `make coc`
+| [suan/vim-instant-markdown](https://github.com/suan/vim-instant-markdown) | Shows a preview of your Markdown file in your browser | `make markdown`

scripts/activate-markdown

@@ -0,0 +1,47 @@
+#!/bin/bash
+
+missingCommands=""
+
+npm --version > /dev/null 2>&1
+
+if [ $? -ne 0 ]; then
+    missingCommands="- npm"
+fi
+
+xdg-open --version > /dev/null 2>&1
+
+if [ $? != 0 ]; then
+    missingCommands="${missingCommands}\n- xdg-utils"
+fi
+
+curl --version > /dev/null 2>&1
+
+if [ $? != 0 ]; then
+    missingCommands="${missingCommands}\n- curl"
+fi
+
+if [ "$missingCommands" != "" ]; then
+    echo -e "You have to install the following commands before installing this extension:\n$missingCommands"
+    exit 1
+fi
+
+which instant-markdown-d > /dev/null 2>&1
+
+if [ "$?" -ne 0 ]; then
+    echo "This plugin needs you to install the following NPM package: https://www.npmjs.com/package/instant-markdown-d"
+    echo "Please install it and restart this script to activate this plugin."
+    exit 1
+fi
+
+echo "Activating Markdown support..."
+
+sudo npm -g install instant-markdown-d
+
+cat ~/.vimrc | sed "s/\" Plugin 'suan\/vim-instant-markdown'/Plugin 'suan\/vim-instant-markdown'/" > ~/.vimrc.tmp
+rm ~/.vimrc
+mv ~/.vimrc.tmp ~/.vimrc
+vim +PluginInstall +qall
+
+echo "Markdown support has been activated!"
+echo "If you like this plugin, don't forget to send your ♥ to its author: https://github.com/suan/vim-instant-markdown"
+

vimrc

@@ -21,6 +21,9 @@ call vundle#begin()
 
 Plugin 'VundleVim/Vundle.vim'
 
+" Markdown live preview
+" Plugin 'suan/vim-instant-markdown'
+
 " Asynchronous linting/fixing for Vim and Language Server Protocol (LSP)
 " integration - https://github.com/w0rp/ale
 Plugin 'w0rp/ale'