[clang-tools-extra] [clang-tidy][NFC] Remove trailing whitespaces in documentation (PR #167103)

[Baranov Victor via cfe-commits]

vbvictor wrote:

> I think we usually add these kinds of formatting-only commits to [`.git-blame-ignore-revs`](https://github.com/llvm/llvm-project/blob/af456dfa111bbfc54950fd56a95a446488add406/.git-blame-ignore-revs)? Otherwise LGTM

Yeah, after they get merged.

https://github.com/llvm/llvm-project/pull/167103