Nuntius0

Add dark theme

5

Adds a dark theme, addressing #3. Per default it will follow the system theme (on systems that support it, else be white). This includes definitely Android Q and LineageOS 16,...

Undo snackbar

4

Fixes #29. The FAB needs to be wrapped in a parent CoordinatorLayout and the snackbar needs to be called on this parent instead of the bigger `content_frame`, otherwise the snackbar...