Remove silverstripe-themes github org (and move repos elsewhere)

silverstripe-themes · GitHub. Having a separate org makes it hard to maintain contributor groups. That’s already tough on SilverStripe Ltd. · GitHub for 100+ repos.

The only theme we really use from there is GitHub - silverstripe-themes/silverstripe-simple: The "Simple" theme for SilverStripe by Sara (Innovaif). Winner of the 2012 theme competition.. We’re already hosting other themes on (see SilverStripe Ltd. · GitHub). So I’m proposing we move the simple theme there as well. This shouldn’t affect any composer installs, since the identifier in packagist stays the same.

For the other themes, they’re no longer maintained. I propose moving them to SilverStripe Archive · GitHub

Sounds sensible to me!

OK, done! Kept the org empty, otherwise it won’t redirect properly: silverstripe-themes · GitHub. Moved everything apart from silverstripe-simple to