Clarify the weights that identify issues for beginners

CONTRIBUTING.md

@@ -100,8 +100,7 @@ the remaining issues on the GitHub issue tracker.
 
 ## I want to contribute!
 
-If you want to contribute to GitLab, but are not sure where to start,
-look for [issues with the label `Accepting Merge Requests` and small weight][accepting-mrs-weight].
+If you want to contribute to GitLab, [issues with the label `Accepting Merge Requests` and small weight][accepting-mrs-weight] is a great place to start. Issues with a lower weight (1 or 2) are deemed suitable for beginners.
 These issues will be of reasonable size and challenge, for anyone to start
 contributing to GitLab.