New users of Agile Toolkit rely on documentation. To make it easier for the maintainers to update documentation - each component of ATK framework comes with a nice documentation builder.
Open file "docs/index.rst" in your editor. Most editors will support "reSTructured Text" through add-on. The support is not perfect, but it works.
If you are updating a feature - find a corresponding ".rst" file. Your editor may be able to show you a preview. Modify or extend documentation as needed.
See also: http://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html
Make sure you have "Docker" installed, follow simple instructions in "docs/README.md".
You can integrate PhpStorm build process like this: