Changes:

• #333 RealtimeCSG can now be imported as a package using Unity Package Manager.
• #333 Icons are embedded into a generated class, which reduces clutter in the texture browser.
• #335 #340 An assembly definition was added for versions of unity that support it. Any versions older should treat RealtimeCSG as if it were a standard plugin in Plugins/
• #340 Readme updated to include information on how to import the project with supported methods, and formatting adjusted to be easier to read.
• #340 Included information on how to contribute to the project
• Included changes from #341

Known Issues:

• (Fixed by #343) ~~Compilation error on 2020.3.13 and older, with AssetDatabase.SaveAssetIfDirty, where this API does not exist.~~
• (Unity issue/Can't be fixed) RealtimeCSG cannot be fully removed without closing Unity first, due to use of native/C++ dll. A solution to this is closing Unity, and manually deleting the RealtimeCSG folder.