Merging of NEW themes is paused for a little while

[bep]

The momentum of AI has created some new challenges for us that we need to fix on a more foundational level before unpausing this:

• Asking Claude to "create me a pretty Hugo blog theme with a blue palette" creates a decent looking theme in a minute.
• This means that with the current setup it can take longer to review and merge a new theme than it took to create it in the first place.
• It also means that we end up with a whole lot of themes that's not really themes; they're not very extensible and it may make more sense to start from scratch.

There are several problems described in the above, but short term I'm going to come up with a new set up of rules for a theme on a form that a machine can understand:

• With soft rules that needs to be fixed before merge (e.g. missing thumbnail).
• Hard rules that means we will reject the theme.
• And also a way of rating a theme based on some set of criterias.

I will follow up on this,