Editorial: fixes to suppress bikeshed warnings

[takikawa]

This is a minor editorial PR that fixes most of the bikeshed warnings and adjusts linking (in particular, makes sure "map" links to the infra spec where appropriate).

There are just two warnings left after this PR:

LINE 683: Unexported dfn that's not referenced locally - did you mean to export it?
<dfn bs-line-number="683" data-dfn-for="index-map" data-dfn-type="dfn" id="index-map-offset" data-lt="offset" data-noexport="by-default" class="dfn-paneled"><code bs-line-number="683" class="highlight">offset</code></dfn>
LINE 687: Unexported dfn that's not referenced locally - did you mean to export it?
<dfn bs-line-number="687" data-dfn-for="index-map" data-dfn-type="dfn" id="index-map-map" data-lt="map" data-noexport="by-default" class="dfn-paneled"><code bs-line-number="687" class="highlight">map</code></dfn>

We could remove these dfns but we could also link them when we flesh out the index map sections in the future.