The current README is 13 years old and says things like
...At the moment configuration is split between an incomplete Cinnamon Settings and a heavily patched Gnome Control Center.
One of these two tools need to be removed from the default installation and discontinued in the scope of the Cinnamon project. The other one needs to be able to load all modules, whether they're GNOME modules or Cinnamon settings modules....
It gives a wrong impression as if Cinnamon is an experimental and incomplete project -- it needs to be updated to reflect the current situation that Cinnamon is an independent and mature project.