[clang-tools-extra] Adding first version for which clang-tidy checks and their options are available (PR #162937)

[Baranov Victor via cfe-commits]

vbvictor wrote:

> To make sure I understand properly what you mean: once the script is reviewed and approved, I should merge it with add_new_check.py file so the versions are then automatically generated for the docuementation?

I think we should patch `add_new_check.py` so that it would automatically set current LLVM version in proper places. How we patch the script depends on complexity: we can just copy-paste needed functions in `add_new_check.py` from your script or refactor needed utility functions in a separate module and reuse that module in `add_new_check.py`. But I guess copy-pasting would be enough. 

https://github.com/llvm/llvm-project/pull/162937