Hotkey version 2

[theinterned]

This is a tracking issue for hotkey version 2 which will introduce a few breaking changes:

• fixes eventToHotkeyString returns doubled "modifier" when "key" is a modifier #64 fixes a bug with duplicate modifier keys.
• Fix querySelector by quoting templated value #57
• Support comma as a hotkey #71

Some planned work was moved to v3 #74

[theinterned]

v2 was released https://github.com/github/hotkey/releases/tag/v2.0.0 so I'm going to close this and move the outstanding items to a "v3" issue #74