Add hotkey Rated 5 out of 5 stars

I think this addon will be better if you add hotkey to show/hide bookmark bar. Ex. in addon Sage++ that I'm using to read RSS, we can show/hide RSS bar by press Alt+Z. So, it's great if we add the hotkey (such as Alt+A) to this addon.

This review is for a previous version of the add-on (3.2).