The Atom editor can give you a live updating preview while editing RST files. RST files are used for documentation of code (and at least one graduate thesis has been written in RST) due to it being more flexible than Markdown yet not as complicated as LaTeX. Bitbucket and Github render RST just as they do Markdown for README.rst files.
With Atom, you need to install a plugin to work with RST live preview editing. You can certainly edit without the plugin, but you need the plugin to get live preview in Atom with rst-preview or rst-preview-pandoc.
.deband install by
Install RST preview plugins for Atom
apt install pandoc git
Start Atom, and click Packages/Settings > View/Install Packages
see a live updating preview by pressing ctrl shift e (once)