Add mention of Discord to drop-in blurb

Author: dangerworm

pages-events/events-drop-ins.html

@@ -8,9 +8,10 @@ <h2>Drop-in Sessions</h2>
     more.
 </p>
 <p>
-    Jitsi links for regularly-scheduled sessions will be added to the web site a little before each drop-in event, but
-    we have a permanent Jitsi room set up at <a href="https://join.codewith.org.uk">https://join.codewith.org.uk</a>.
-    You can also click the 'Jitsi Link' buttons below.
+    We either use Jitsi or Discord for our regularly-scheduled sessions. Invitation links will be added to the Slack
+    group and to the event ticket a little before each drop-in event. We also have a permanent Jitsi room set up at
+    <a href="https://join.codewith.org.uk">https://join.codewith.org.uk</a> which you can join to ask questions
+    even when there's no event running.
 </p>
 
 <section id="events-drop-ins">