Docs-Vim wót darthnithin

This simulates very limited versions of vim's insert and normal modes on Google Docs.

Currently supported features:

Insert mode:
Typing
Escaping to normal with Esc
Escaping to normal with a two-key combination
Normal mode
Getting to insert mode with the "i" key
Moving with the home-row keys
Repeated motions using the number keys
Delete a single character with the "x" key
Enter visual mode with the "v" key
Visual mode
Getting to normal mode with Esc
Moving with the home-row keys
Repeated motions using the number keys
Delete selected text with the "x" key