[clang-format] [doc] Add script to automatically update help output in ClangFormat.rst.

Fixes https://github.com/llvm/llvm-project/issues/54418.

Reviewed By: MyDeveloperDay

Differential Revision: https://reviews.llvm.org/D121916

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GitOrigin-RevId: a45ad3ca8ce78988a4d51b432455ce0ddddbbf13
1 file changed