Webpage to check repository "readiness" for inclusion in gallery

[amis92]

A form on gallery website to put repository url into and check "readiness":

1. Are there any game systems and catalogues
2. Are datafiles in non-zipped format (cat/gst)
3. Is there a catpkg workflow
4. Is there a release with a catpkg

Provide instructions how to add one's repository to the gallery.