Update clang-tidy docs to fix argument passing.

When using `tidy_checks` if the first part of the value is `-*` then
this gets turned into an argument by `argparse`. If you escape to be
`\-*` then it gets passed through as escaped and seems to be ignored by
clang-tidy. This CL updates the documentation to use the
`tidy_checks='-*'` version so argparse recognises it as the value and
passes through correctly.

Change-Id: I5db28dbea5c4ff994b1d9e518090bdc91c79abe5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4811655
Commit-Queue: dan sinclair <dsinclair@chromium.org>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1188007}

docs/clang_tidy.md

@@ -104,7 +104,7 @@ $ ${chromium_build}/recipes/recipe_modules/tricium_clang_tidy/resources/tricium_
     --out_dir out/Linux \
     --findings_file all_findings.json \
     --clang_tidy_binary $PWD/third_party/llvm-build/Release+Asserts/bin/clang-tidy \
-    --tidy_checks '-*,YOUR-NEW-CHECK-NAME-HERE'
+    --tidy_checks='-*,YOUR-NEW-CHECK-NAME-HERE'
     --all
 ```