Currently a selected file can be added to be staging area using either space or ctrl-shift-+ when already selected. However there is no easy way to select the first non-staged file, nor is there a way to (easily) scroll the selected file.

The basic workflow that needs support using only the keyboard is as follows:

1. Select first non-staged file (this should allow using the arrow keys to move up and down the non-staged files list)
2. Scroll through diff view
3a. Add entire file (this is currently possible) and select next file in non-staged list
3b. Stage hunk and keep non-staged file selected
3c. Stage lines and keep non-staged file selected (this part is nice to have)
4. Commit (currently possible)