Add keyboard navigation/shortcuts to chrome extension

I typically have a popped out join window directly next to my main chrome browser for quickly texting/calling contacts, and it would be really nice to be able to have keyboard shortcuts to:

- navigate between SMS/Notficiations (ctrl+tab or similar)
- contact search (forward slash)
- arrow down through (or use j/k like in gmail) each SMS conversation (or list of contacts when doing a contact search)
- shortcut for SMS (enter) vs call (shift+enter or "c") on a contact