I included new code in the current pull request
that parses text wrapped in double brackets to render it as an internal page link. The generated link will be appropriate for whatever channel owns the wiki, even if they clone the wiki to their channel (not yet implemented).
[[a page name]]
gets rendered as
<a href="/wiki/channel/wikiname/a+page+name">a page name</a>
I'm going to need some help sorting out all this urlencode/escape_chars nonsense at some point.