Add hint for Enforcement Status for Rulesets (#36807)

Co-authored-by: Ben Ahmady <32935794+subatoi@users.noreply.github.com>

Author: david-graesser

data/reusables/repositories/repo-new-ruleset.md

@@ -1,3 +1,4 @@
 1. Click **New ruleset**.
 1. Click **New branch ruleset**.
 1. Under "Ruleset name," type a name for the ruleset.
+1. To activate the ruleset, under "Enforcement Status", select **Active**.