Adding clipboardRead permission

[bunnybooboo]

From MDN
"You can use the "cut" and "copy" commands without any special permission..."
but
"To use the "paste" command, you must have the "clipboardRead" permission"

Adding this allows pasting from the contextual menu.

[bunnybooboo]

Editing WebExtension manifest.json commands suggested_key via clash with Firefox reserved downloads keyboard shortcut: Ctrl + Shift + Y

Previous Firefox add-on had Ctrl + Alt + V, which is not permissible in a WebExtension. The secondary modifier "must be 'Shift'". Alt + Shift + V is reserved inside Gnome (I'm testing in Arch Linux and it seems to perform same action as Alt + V but also supposedly reserved in Orca screen reader.)

Suggested fix Alt + Shift + Y

[bunnybooboo]

This then provides the popup clippingKey.html which needs further work. Today I right clicked the popup to propagate with its guiding text, however the key action via the paste-shortcut-key does not work as expected. EDIT: and the paste now works as expected.

[aecreations]

Thanks for submitting this! Yeah, I did add the clipboardRead permission when I tried to implement New From Clipboard, but that didn't work on Firefox. As mentioned, there were no issues on Google Chrome. Thanks for catching the potential conflict with CTRL+SHIFT+Y.