#3 - (Base settings) - theme, mode, colors

[Aeri4a]

Part 1:
[UI]

1. Settings page
2. Theme & dark/light mode set component
3. Side panel with color palette

Part 2:
[Functionality]

1. Definition of SCSS file
2. Add all themes - can be separate files
3. Settings load from localStorage [function 1]
4. Apply settings changes (theme/mode) [function 2]