[clang-tools-extra] [clang-tidy] Rewrite remaining bugprone check docs to Markdown [1/N] (PR #212723)

[Zeyi Xu via cfe-commits]

zeyi2 wrote:

This will likely break the doc8 linter and documentation build, but I'd prefer not to use `gh stack` here. Any changes would likely require a force-push, rewriting the commit history and marking existing review comments as outdated.

https://github.com/llvm/llvm-project/pull/212723