Instead of having all style duplicated and re-using a base, we just hack
into the funciton that queries the dark/light theme based on the style
suffix known at compile time.
This removes one of the problem that happens when trying to work on the
widget style with the extension, as it relies on include path hacks
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"
