Link definitions in syntaxes

Love that spirit, @motopascyyy! Thanks for pitching in. Not wiki-linked hashtags, just a syntax definition with wiki-links and hash-tags. So I could have both [[link to draft]] and #awesome_hashtag picked up without having to switch syntaxes.

Plan is to point it towards the block level filter action I’ve been rambling about recently; that’ll call up not just the drafts, but individual paragraphs that contain that tag. For example, I could have a #follow_up tag, and click on it to pull up a list of all items I want to follow up on. Or anything else that might benefit from that kind of surfacing…