[FEATURE] Use gnome shell v40 as default

[RouHim]

Is your feature request related to a problem? Please describe.
There is an increasing number of bug reports in the issue section complaining about broken visualization of the gnome shell > v40 with the dracula theme.
This is due to the fact that more and more distros are now using > 40 gnome shell versions.
(#124, #141, #147, #148, #163, #162, #166, #186, #182, #213, #211, #217, #226, #245, #220, #256, ...)

Describe the solution you'd like
Use the v40 version as default and provide a "legacy" folder that preserves the old data for the pre v40 era.

Describe alternatives you've considered
It would also be possible to fork this project and provide an explicit v40 version of this package.

Additional context
I would also improve the documentation regarding this topic.