REBUS:
- Repair form validation (Remove required attributes, issue #166)
- Remove Kanboard settings (issue #206)
- Resort categories (issue #176)
- Show all rooms by presentation device issues (issue #204)
- Add toast if form isn't valid

Refactor installation manual | Delete some useless files | Merge requirements of pip in requirements.txt | Remove .idea

display five individual timetables for every day instead of one timetable for every day on mobile devices

Navigation arrows, comments, better presentation of week days, add navigation items of smart plan to print mode, remove some margins, remove django material imports in header, add media dir to .gitignore