Formatting nit

CONTRIBUTING.md

@@ -36,7 +36,9 @@ The rationale for this is that YAPF was initially developed at Google where
 these two exceptions are still part of the internal Python style guide.
 
 ## Getting started
-YAPF supports using tox 3 for creating a local dev environment, testing, and building redistributables. See [HACKING.md](HACKING.md) for more info.
+YAPF supports using tox 3 for creating a local dev environment, testing, and
+building redistributables. See [HACKING.md](HACKING.md) for more info.
+
 ```bash
 $ pipx run --spec='tox<4' tox --devenv .venv
 ```