[clang] [Clang][Docs] Fix malformed code-block directive in MSan and TSan docs (PR #190461)

[Thurston Dang via cfe-commits]

thurstond wrote:

@DarkPhoenix42 Please use a public email address for GitHub, per LLVM policy (https://llvm.org/docs/DeveloperPolicy.html#email-addresses):

> The LLVM project uses email to communicate to contributors outside of the GitHub platform about their past contributions. Primarily, our buildbot infrastructure uses emails to contact contributors about build and test failures.
>
> Therefore, the LLVM community requires contributors to have a public email address associated with their GitHub commits, so please ensure that “Keep my email addresses private” is disabled in your [account settings](https://github.com/settings/emails). There are many free email forwarding services available if you wish to keep your identity private.


https://github.com/llvm/llvm-project/pull/190461