Suggestion for keybinding scope in README

I immediately tried to map autocomplete to the `esc` key (I'm coming from TextMate). Once I had done so, the `esc` key would no longer do useful things, like close the ‘find’ pane, and dismiss the command palette.

Using `.active.pane` as the scope instead of `.editor` fixed my problem!
Merge pull request #15 from steveluscher/patch-1

Suggestion for keybinding scope in README