Add calendar for open source podcast (#633)

Author: juanis2112

calendars/podcast.yaml

@@ -0,0 +1,10 @@
+name: Podcast Calendar
+timezone: America/Los_Angeles
+events:
+  - summary: Another Open Source Podcast
+    description: |
+      A podcast about open source! Join us for discussions on open source
+      events, documentation, developer testimonies, mentorship programs and more."
+    begin: 2024-05-10 11:00:00
+    end: 2024-05-10 12:00:00
+    url: https://discord.gg/X3fpKzKf