Change default 'set tabs aside' shortcut

[aamott]

This shortcut can cause problems for those who are accustomed to using it to go back in history. In Chrome and Edge, it seems to be overridden. Shift+Alt+Left is an unused key combo.

Implements following issue: Default shortcut overrides browser hotkeys #89

Changelog

• Changed "Set Tabs Aside" shortcut to Shift+Alt+Left

[aamott]

Got that updated. Thanks!

[aamott]

Accidentally clicked "close and comment"...