Making this PR to demonstrate the changes I found necessary to get UdonSharp working in the new VRChat Package Manager:
Add package.json file with Samples and new 'url' and 'gitDependencies' members (will reach out privately with some more info on these)
Move the "Updater" folder to within "Editor" (UPM structure only allows Runtime, Editor, Samples~ and Tests folders in the root)
Rename "Examples" to "Samples~" to follow UPM structure
Rename "Tests" to "Tests~" - this keeps Unity and U# from trying to load the contents. I was getting issues about needing to define a U# assembly, we can tackle that separately if you intend for these tests to be included for the end user.
Making this PR to demonstrate the changes I found necessary to get UdonSharp working in the new VRChat Package Manager: