Update CONTRIBUTING.md

Intentionally not signing this commit to make sure the automated DCO check behaves as expected.

Author: susodapop

CONTRIBUTING.md

@@ -67,7 +67,7 @@ Signed-off-by: Joe Smith <[email protected]>
 Use your real name (sorry, no pseudonyms or anonymous contributions.)
 ```
 
-If you set your `user.name` and `user.email` git configs, you can sign your commit automatically with git commit -s.
+If you set your `user.name` and `user.email` git configs, you can sign your commit automatically with `git commit -s`.
 
 ## Set up your environment