[libc] [llvm] [libc][docs] add redirect for math/index.html (PR #120274)

[Aiden Grossman via llvm-commits]

boomanaiden154 wrote:

> pip install -r llvm/docs/requirements.txt BEFORE running ninja <whatever to build docs>.

This is what we should be doing. I think a couple other bots already do it. Should be a relatively simple zorg patch.

https://github.com/llvm/llvm-project/pull/120274