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

[Balázs Benics via cfe-commits]

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@@ -7,6 +7,24 @@ Both provide a way of driving the analyzer, detecting compilation flags, and gen
 CodeChecker is more actively maintained, provides heuristics for working with multiple versions of popular compilers and it also comes with a web-based GUI for viewing, filtering, categorizing and suppressing the results.
 Therefore CodeChecker is recommended in case you need any of the above features or just more customizability in general.
 
+Machine-readable output
+-----------------------
+
+For a direct analysis of a source file, the ``clang`` driver can write a SARIF report that is suitable for automation and AI agents::
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steakhal wrote:

```suggestion
For a direct analysis of a source file, the ``clang`` driver can write a SARIF report::
```

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