[clang-tools-extra] [clang-tidy][NFC][doc] improve "options" sections of `misc-`, `cppcore-` and other checks (PR #133694)

[via cfe-commits]

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@@ -78,6 +78,6 @@ Options
         co_await wait();
       }
 
-    Eg: ``my::safe::awaitable;other::awaitable``
-    The default value of this option is empty string `""`.
+    Eg: `my::safe::awaitable;other::awaitable`
+    The default value of this option is an empty string.
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EugeneZelenko wrote:

```suggestion
    Default is an empty string.
```

https://github.com/llvm/llvm-project/pull/133694