Move wiki into main repo as a submodule

[nickmeinhold]

Is your feature request related to a problem? Please describe.

Currently we do not necessarily know when the wiki has been updated.

Also, keeping separate repos for the wiki and the project is extra clutter.

Describe the solution you'd like

Move the wiki into the main repo as a submodule.

Describe alternatives you've considered

Setup a webhook

• How can you track or be notified of changes to GitHub wikis? - Stack Overflow

Additional context