[clang-tools-extra] [clang-tidy] Update google todo checker with style guide changes. (PR #165565)

[Quentin Khan via cfe-commits]

================
@@ -9,3 +9,14 @@ The relevant style guide section is
 https://google.github.io/styleguide/cppguide.html#TODO_Comments.
 
 Corresponding cpplint.py check: `readability/todo`
+
+Options
+-------
+
+.. option:: Style
+
+   A string specifying the TODO style for fix-it hints. Accepted values are
+   `Hyphen` and `Parentheses`. Default is `Hyphen`.
----------------
qukhan wrote:

I would like to push back on this if possible as this ensures that the fix-its will *suggest* the new style which is preferred for [Google coding conventions][1]. There won't be a flurry of warnings on existing TODO comments and manually typing a comment matching the `Parentheses` style won't trigger warnings either.

[1]: https://clang.llvm.org/extra/clang-tidy/#:~:text=Checks%20related%20to%20Google%20coding%20conventions.

https://github.com/llvm/llvm-project/pull/165565