[clang-tools-extra] [clang-tidy] add fixhint for misc-use-internal-linkage (PR #96203)

[Piotr Zegar via cfe-commits]

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@@ -25,3 +25,16 @@ Example:
   }
   // already declared as extern
   extern int v2;
+
+Options
+-------
+
+.. option:: FixMode
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PiotrZSL wrote:

should say what is default value

https://github.com/llvm/llvm-project/pull/96203