[libc] Add documentation for clang-tidy checks.

Reviewers: sivachandra

Reviewed By: sivachandra

Subscribers: tschuett, ecnelises, libc-commits

Tags: #libc-project

Differential Revision: https://reviews.llvm.org/D82846

GitOrigin-RevId: ab25ed26c67e5d540e6628fa5e5982e7e9b90a38
1 file changed