Jumpto Plugin: Get h1 Title, not Filename

[kawa-kokosowa]

From a coworker:

Feature suggestion for AdventureDocs: make it dig into the destination for the first <h#> tag (err, whatever the MD version of that is) and pull its contents into here, instead of just displaying the raw anchor ID, which could potentially be a really ugly generated value.
That might get more complicated than it sounds, by either opening tons of other file handles, or requiring "two-pass" processing. But maybe you're already doing that, since you've got crosslinked hash IDs, after all...