Update .CONTRIBUTING.md

Co-authored-by: Erin Shaben <eshaben@icloud.com>

.CONTRIBUTING.md

@@ -222,7 +222,7 @@ To use Vale locally to screen your work:
 2. From the `polkadot-mkdocs` directory, run the following in your terminal:
 
     ```bash
-      vale (INSERT_PATH_TO_FILE)
+    vale INSERT_PATH_TO_FILE
     ```
 
     The output will look something like: