Commit e0a41d3a25 ("kde: replace systemd unit with AutostartScript for
theme application (#708)") improved theme application robustness to the
point of resetting custom theming options. Adding a decorations option
allows overriding its default value without it being reset.
This change also polishes the entire module.
Link: https://github.com/danth/stylix/pull/772
Reviewed-by: NAHO <90870942+trueNAHO@users.noreply.github.com>