Backend/database_methods library

1. mad2_groups package
2. documentation
3. Backend/database_methods.dart

mad2_groups package

1. Libraries
2. Backend/auth_methods
3. Backend/database_methods
4. Backend/group
5. Backend/shared_preference_helper
6. firebase_options
7. Frontend/group_landing_page
8. Frontend/group_list_builder
9. Frontend/group_widget
10. Frontend/groups_page
11. Frontend/sign_in
12. Frontend/view_all_members_group
13. main