Add run() function and document it
Add run() function and document it

The doc comment outlines my plan about cleaning up this function.

dannydulai/alacritty,jwilm/alacritty,alacritty/alacritty,jwilm/alacritty,jwilm/alacritty,alacritty/alacritty,dannydulai/alacritty,jwilm/alacritty