docs: update shellcheck cmd

paulirish · paulirish · commit 05e2a1aca017 · 2019-08-28T11:35:49.000-07:00
diff --git a/hacking-and-testing.md b/hacking-and-testing.md
@@ -33,4 +33,4 @@ You can lint your scripts via shellcheck, our CI bots will also check.
 
 ```sh
 brew install shellcheck
-shellcheck diff-so-fancy update-deps.sh
+shellcheck *.sh
