This is the Wiki for LewMC projects, found at wiki.lewmc.net
You can download JetBrains Writerside from https://www.jetbrains.com/writerside/, it's currently free during early access.
You can then create a new project from VCS and enter https://github.com/lewmc/wiki to download the project, edit it and create pull requests.
Download the project using Git, then you can edit the files directly in the 'Writerside' directory.