Yes. I have seen the .mdown extension also, but .md is the default in every editor I've used, and it's a default for readme files on Gitlab and GitHub.
The gift suggestions need a bit of fine tuning. Body hair bleach, ping pong paddles, and kitchen accessories are perhaps not advisable as gifts for the women in your life.
Looking at the wiki, I don't think it does handle them. I reckon that if jehna when to the trouble of making this, he knows of at least one use case, even if it's his own. I appreciate that he's shared his work. That said, from my own experience, by the time a regular expression becomes difficult for me to parse, there are subexpressions, negative lookbehinds, and other less comprehensible regex features that this library doesn't seem to support.
For me, the history of my text messages is a feature, not a flaw. I'm assuming this is "Snapchat for texts." We've already seen that Snapchat can't guarantee that photos aren't saved. The same limitations will almost certainly apply to Skim. So will this be anything more than a crippled texting app?
The benefit of an online listing is easy access to package descriptions and repositories. When there are multiple packages for a given task, I'd like to know which is more heavily updated and supported. Correct me if I'm wrong, but I don't believe there's a way to open the Github page from that menu.
There's a small link to the repository in the meta line below each project description, next to the last modified date. It's hard to find. I was coming here to suggest that on package detail pages, the package name should link to the project repository, and not recursively to the detail page. That was my instinctual expectation.