make gloobus-preview.desktop xdg-mime ready

[quequotion]

I'm surprised to find that gloobus-preview.desktop cannot be used to open files with xdg-mime and does not contain any mimetype associations. With a few changes it's possible to ensure gloobus-preview always appears in the list of available applications to open its supported files with.

Attached is an example, with "%u" appended to the "Exec=" line and a ton of associations copy-pasted from gimp (image formats), mpv (a/v formats), and libreoffice-write (document formats) into "MimeType=". The mime associations are serious overkill and more than likely include types gloobus cannot yet open; someone more familiar with gloobus could sort through them quickly.

Note, this does not override a user's default applications or set gloobus-preview as a default application for anything, just hint to xdg-mime that there is an application available for these types and it is gloobus-preview.