bug#69651: 30.0.50; Theme-agnostic hook for theme loading

[Andrea Ciceri]

Modus themes provide an hook for theme loading and the manual even
suggests a way to implement an agnostic hook that works for all the
themes using advices:

https://www.gnu.org/software/emacs/manual/html_node/modus-themes/A-theme_002dagnostic-hook-for-theme-loading.html

Why isn't such an hook provided upstream?

This is the first time I use the GNU bugs tracker and this is more like
a "kind request" than bug, I hope I did everything correctly.

If you confirm that it makes sense and should be added then I can try to
send a patch by myself (I'm not familiar with Emacs internals so
probably I need to figure out where this should be added before).

Thanks!


Andrea