Update docs/MAINTAINING.md

Author: jsjoeio

docs/MAINTAINING.md

@@ -44,7 +44,7 @@ We use the following process for triaging GitHub issues:
 1. a submitter creates an issue
 2. add appropriate labels
    1. if we need to look further into it, add "needs-investigation"
-3. add to a milestone
+3. add to milestone
    1. if it should be fixed soon, add to version milestone or "On Deck"
    2. if not urgent, add to "Backlog"
    3. otherwise, add to "Backlog Candidate" if it should be considered