Use valid data in our GetCommit example response

When validating parsing, copy pasting should just work, but
instead we created

doc/api/commits.md

@@ -196,9 +196,9 @@ Example response:
   "last_pipeline" : {
     "id": 8,
     "ref": "master",
-    "sha": "2dc6aa325a317eda67812f05600bdf0fcdc70ab0"
+    "sha": "2dc6aa325a317eda67812f05600bdf0fcdc70ab0",
     "status": "created"
-  }
+  },
   "stats": {
     "additions": 15,
     "deletions": 10,