docs: fix references in public docs

[JosephLenton]

Which issue does this PR close?

• Closes Fix current docs build issues #2938

What changes are included in this PR?

• Links to external sites are made clickable. This is changing from https://example.com to <https://example.com>.
• References to internal APIs are removed. The comment is the same, but the doc link is gone.
• Trailing triple slash opening a code snippet, but never closing it, are removed.

Are these changes tested?

These changes were QA'd by running cargo doc --no-deps.

AI Disclosure

I got Claude to do most of the changes in this PR.