Revert "name change"

This reverts commit e65e1031a97a8a20bee8b08753970d67e9d29de3.

Using night_mode would lead to strange behaviour as the style would be inverted (again) on AnkiDroid.
Merge branch 'develop' into feature-ospalh-special

Conflicts:
	local_css_and_diy_night_mode.py

I know what i am doing. Do name it night_mode just for me.