Add missing newline

Co-authored-by: Mike West <[email protected]>

Author: carlosjoan91

index.bs

@@ -1830,6 +1830,7 @@ Content-Type: application/reports+json
   3. Return the result of executing the <a>URL serializer</a> on |result|.
 
   <h3 id="strip-https-url" algorithm>Strip HTTP(S) URL</h3>
+
   Given a [=/URL=] |url|, this algorithm returns the URL with potentially
   sensitive fields blanked.