There are now a few freetype-specific functions in the API so we need seperate bindgen output for it
Duplicates the imgui code somewhat unnecessarily, but shouldn't impact repo size much due to git's compression
Previously if you checked out a different rev of imgui submodule, this would be clobbered
With this change, you can checkout any revision of imgui, run bindgen, build, test, then commit change to the submodule
The autofix is still available via 'cargo task modfix'