[clang] docs(clang): add some missing flags (PR #209519)

[Balázs Benics via cfe-commits]

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@@ -239,4 +257,3 @@ Detailed Usage
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 For extended documentation please refer to the `official site of CodeChecker <https://github.com/Ericsson/codechecker/blob/master/docs/usage.md>`_!
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steakhal wrote:

Why is this line removed? It shouldn't appear in the diff if you didn't change anything here.

https://github.com/llvm/llvm-project/pull/209519