[llvm] [Github] Add clang-tools-extra docs to CI (PR #69827)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> LGTM.

Thanks for the reviews on all of these @tstellar. Probably should've consolidated them a little bit better to make it easier on your end but wanted to make sure I wasn't missing any project specific subtleties.

https://github.com/llvm/llvm-project/pull/69827