Thorough documentation for SpongePowered/Mixin.
The maintainers of Mixin don't have a ton of time on their hands to write some of the articles on Mixin that were promised, I have taken it upon myself to write them.
To run the site locally, you need Python 3 to be installed.
To install dependencies, run pip install -r requirements.txt.
Next, to run the site, run mkdocs serve.