[Feature] Fullscreen Keyboard Shortcut

[quantenProjects]

I have searched the existing feature requests to make sure this is not a duplicate request.

• Yes

The feature

If I haven't missed something¹, there is currently no keyboard shortcut for the fullscreen mode. I would suggest using the key "f" as it is the usual shortcut in other webapps.

F11 in the browser doesn't work in the same way. For example, I use Firefox with the tab bar to the left and it is not hidden when using F11, but is when using the fullscreen button from the pause-menu of immich-kiosk.

¹https://docs.immichkiosk.app/misc/navigation/#keyboard-shortcuts doesn't list it and I can't find a call to handleCustomKeyboardAction that actually uses the customKeyboardActions.FULLSCREEN-case (I only found these)

[quantenProjects]

I have tried to create a pull request for it, but not been able to test it, feel free to take it or do it newly: #756

[damongolding]

The custom functions are for binding actions to the up and down arrow. I've updated the docs to reflect this.

I've also created #757