Updated the version from 1.1 to 1.2
Renamed the header to "Slint Royalty-free Desktop, Mobile, and Web Applications License"
Added definition of "Mobile Application" and grant of right
Moved "Limitations" to 3rd section and "License Conditions - Attributions" to 2nd section
Added flexibility to choose between showing "MadeWithSlint" as a dialog/splash screen or on a public webpage
Moved the para on copyright notices to section under "Limitations"
This avoid repeating the enums both in the compiler and in
the runtime library, and register them in a bunch of other places.
So it should be easier to add enums and enum values
Since cbindgen doesn't see through the macro, generate the enum
manually
