Allow permanent link to be wrapped
Bootstrap doesn't wrap the permanent link inside its
<pre> block, but if that link contains an IPv6 address it gets too long to be printed out. That somewhat defeats the purpose of the permanent link. Maybe there's a way to tell Bootstrap to wrap the link. And maybe we can help by including a "zero width space"
​somewhere in the link, which is what we did to wrap fingerprints in the technical details section.