[clang-tools-extra] [clang-doc] [feat] add --repository-line-prefix argument (PR #131280)

[Paul Kirth via cfe-commits]

ilovepi wrote:

Yeah that seems reasonable. You'll still want to check the validity of the optionals, which could make the logic a bit less nice, but overall I expect the code to be cleaner than what we have in a lot of places, right now.

https://github.com/llvm/llvm-project/pull/131280