Previously, our auto-linking feature would match `http` in URLs (such as
`http://...`) to the `common/http` package and automatically create a
link to that, which was undesirable. While it is possible to work around
that via `<code class="no-auto-link">http://...</code>`, most people
didn't even realize the issue.
Since in this case it is possible to reliably know it is a false match,
this commit fixes it by applying a custom auto-link filter that ignores
all docs for `http`, if it comes before `://`.
Fixes#31012
PR Close#31051
c6b180380a