[clang-tools-extra] [clang-tidy][doc] Document that ClassMember* options apply only to static … (PR #227600)

[Carlos Galvez via cfe-commits]

carlosgalvezp wrote:

Looking at the rest of the code, it seems *all* `Class*` settings actually refer to *static* class things. So these docs appear to be wrong:

https://github.com/llvm/llvm-project/blob/main/clang-tools-extra/docs/clang-tidy/checks/readability/identifier-naming.md?plain=1#L770


https://github.com/llvm/llvm-project/pull/227600