fix(doc): resolve some doc warnings about unquoted HTML tags

[teor2345]

Motivation

Nightly rustdoc has some new warnings.

Eventually these will be released as stable, and cause our CI to fail.

Review

This is a low priority cleanup.

Reviewer Checklist

• Will the PR name make sense to users?
  • Does it need extra CHANGELOG info? (new features, breaking changes, large changes)
• Are the PR labels correct?
• Does the code do what the ticket and PR says?
• How do you know it works? Does it have tests?

[codecov]

Codecov Report

Merging #5477 (46fa3ec) into main (233220a) will decrease coverage by 0.13%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5477      +/-   ##
==========================================
- Coverage   79.23%   79.09%   -0.14%     
==========================================
  Files         309      309              
  Lines       39351    39351              
==========================================
- Hits        31179    31124      -55     
- Misses       8172     8227      +55