Firstly, thank you for your interest in contributing to our tutorials. We use Jekyll + Markdown for our documentation. To contribute, simply make a pull request (PR) with changes in the Markdown files ...
NOTE: Starting from FreeCAD 1.0, the BIM workbench is fully integrated and merged with the older Arch workbench. There is no need to install this addon anymore. If you are switching to FreeCAD 1.0, ...