[Feature Request] Add solved status to RSS feed

Hi,

I use Outlook to read the forum via RSS and it’s annoying that there’s no way to tell if a topic is already solved without opening it.

The feed already has flags like <discourse:topicPinned> and <discourse:topicClosed>. Any chance we could get a <discourse:topicSolved> too, or maybe just a “Solved :white_check_mark:” note inside the <description> near the <small>1 post - 1 participant</small> line?

Would save a lot of unnecessary clicks.

Thanks

-Robert