Support for multiple windows

[orschiro]

Support the shortcut across multiple windows.

Not using multiple windows myself.

Pull request welcome.

[tgucci]

good idea. bump.

[mental1337]

+1 for this

[orschiro]

Improved with version 47.

The extension now remembers the last two tabs when you go to another window.

[orschiro]

Should be much improved with version 48 and migration to Manifest v3.

Please report any feedback.

Thanks!