* Use standard margins * Some clean up
* Change colors * Replace toolbar in main activity * Initial implementation of ViewModel
* Refactor some classes and clean up * Refresh style on the fly
RecyclerView.Adapter
This commit mainly refactors the adapters by adding spacing, comments and following other guidelines. In addition, it moves from using `BaseAdapter` to `RecyclerView.Adapter` which leads to much cleaner adapter classes. a