[clang] [Clang] Fix LibTooling doc (PR #90441)

[via cfe-commits]

Sirraide wrote:

> This PR wasn't approved and doc is still not fixed :( What to do with this PR?

It somehow just went unnoticed all this time, unfortunately. I’ll approve the other pr since it seems to do the same thing that we’re also doing somewhere else in our documentation, and it’s pretty much what I suggested here anyway.

The comment in `clang/Tooling/CommonOptionsParser.h` still needs to be updated, which the other pr doesn’t do; you can still do that if you’d like. Sorry about the entire confusion here; this is something that shouldn’t normally happen...

https://github.com/llvm/llvm-project/pull/90441