docs: clarify commit message requirements

CONTRIBUTING.md

@@ -397,14 +397,14 @@ A good commit message should describe what changed and why.
 
 1. The first line should:
 
+  * be prefixed with the name of the module being changed; usually this is the
+    same as the M-* label on the PR
+  * start with an imperative verb
   * contain a short description of the change (preferably 50 characters or less,
     and no more than 72 characters)
   * be entirely in lowercase with the exception of proper nouns, acronyms, and
     the words that refer to code, like function/variable names
-  * start with an imperative verb
   * not have a period at the end
-  * be prefixed with the name of the module being changed; usually this is the
-    same as the M-* label on the PR
 
   Examples: