MNT: update urls + add calendar link to commit rights template

Author: tacaswell

templates.md

@@ -20,19 +20,19 @@ We would like to invite you to join the Matplotlib organization on github with
 commit rights to the main Matplotlib repository! (you should have the GH emails
 in your inbox).
 
-Please see https://matplotlib.org/devel/coding_guide.html#detailed-guidelines
+Please see https://matplotlib.org/stable/devel/coding_guide.html#detailed-guidelines
 and remember to be kind during your reviews.
 
 In addition to the discussions on GitHub we have weekly open developer calls
-that you are invited to join (links below) on Thurdays at <MEETING TIME> UTC
-<(their timezone if you know it)>.
+that you are invited to join on Thurdays (links below for agenda, zoom, and calendar).
 
 If you accept, welcome (formally) to the team!
 
-YOUR NAME (on behalf of the SC)
+<YOUR NAME> (on behalf of the SC)
 
 Agendas: https://hackmd.io/@matplotlib
 zoom: https://zoom.us/j/384435716?pwd=WFpxVWxoYXArTDFzN1lWaHNoOE8xZz09
+calendar: https://scientific-python.org/calendars/
 ```
 
 ## Offer triage right