Add AB-memberonly#270 to 04-21-agenda.md

Author: jyasskin

2025/telcons/04-21-agenda.md

@@ -88,6 +88,7 @@ Design Reviews
 ### Plenary Session - [2025-04-24](https://www.timeanddate.com/worldclock/converter.html?iso=20250424T130000&p1=224&p2=43&p3=136&p4=195&p5=33&p6=248&p7=240)
 
 * Breakout Rollup
+* [Arrangement of the Council Github repositories](https://github.com/w3c/AB-memberonly/issues/270) - Question from the AB
 * [Issue Triage](https://github.com/w3ctag/design-reviews/issues?q=is%3Aissue+is%3Aopen+label%3A%22Progress%3A+untriaged%22)
 
 ### Logistics