Hello,

I noticed that some of the variables that can be modified
by the user or as mentioned as such were not defined as custom variable.
These patches to so and correct the group of one of the existing
defcustom.

The patches don't change any of the existing functionality
but only document these variables better and make them easier to modify.
Because of that I set version to Emacs 30.1. Please tell if that's ok.

Good day,

Björn