Issue title: Display Akira version
 Issue body: I'm testing a few different instances of Akira on my system and it would be useful to have the version shown in the GUI somewhere, usually this can be found in an 'About' dialogue, or sometimes thrown into a corner of a system bar.
 Comments: 
 Comment 0: Adding an `About` section in the preferences panel would be a good solution.
As well as listing in there all the Patreon supporters :smile: 
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