Link to Study Group calendars on events page

Author: EllaKaye

events/index.html

@@ -10,8 +10,8 @@ Meetings and events for existing/aspiring R contributors.
 
 * [R Dev Days/Sprints](r-dev-days): Collaborative events to work on contributions to R or infrastructure that supports such contribution. [Google Calendar](https://calendar.google.com/calendar/embed?src=096ece8c4dd2994219c1e504a6d474f7964e16fe18eced1dbdb8d5323ee6297b%40group.calendar.google.com) / [iCal](https://calendar.google.com/calendar/ical/096ece8c4dd2994219c1e504a6d474f7964e16fe18eced1dbdb8d5323ee6297b%40group.calendar.google.com/public/basic.ics).  
 * [R Contributor Office Hours](office-hours): monthly drop-in sessions to help people get started with contributing to R. Discuss work in progress or work together on open bugs/missing translations. [Google Calendar](https://calendar.google.com/calendar/u/0/r?cid=c7b298f30426b575f888ee963ec38a6da1ad6d2dbc27f34d501a72f2d8abb1cf@group.calendar.google.com) / [iCal](https://calendar.google.com/calendar/ical/c7b298f30426b575f888ee963ec38a6da1ad6d2dbc27f34d501a72f2d8abb1cf%40group.calendar.google.com/public/basic.ics).  
-* [C Study Group](c-study-group-2025) (upcoming - February-July 2025): study group designed for R contributors to develop skills in C programming. Calendar links will be shared when timings are finalised. Please fill in [this whenisgood poll](https://whenisgood.net/jqfrg3j) if you're interested in participating.
-<!-- [Google Calendar](https://calendar.google.com/calendar/u/1?cid=ab59b5988cef70d576d045f33a7b4ec633d665afb070aaf696b4b353254c74dc@group.calendar.google.com) / [iCal](https://calendar.google.com/calendar/ical/ab59b5988cef70d576d045f33a7b4ec633d665afb070aaf696b4b353254c74dc%40group.calendar.google.com/public/basic.ics).-->
+* [C Study Group](c-study-group-2025) (February-July 2025): study group designed for R contributors to develop skills in C programming. 
+[Google Calendar](https://calendar.google.com/calendar/u/1?cid=ab59b5988cef70d576d045f33a7b4ec633d665afb070aaf696b4b353254c74dc@group.calendar.google.com) / [iCal](https://calendar.google.com/calendar/ical/ab59b5988cef70d576d045f33a7b4ec633d665afb070aaf696b4b353254c74dc%40group.calendar.google.com/public/basic.ics).
 * [R Contribution Working Group](/working-group): meetings to organize events and work on other infrastructure supporting contributors. [Google Calendar](https://calendar.google.com/calendar/u/0/[email protected]) / [iCal](https://calendar.google.com/calendar/ical/nc4tg39nam44itn9uhnf751hbk%40group.calendar.google.com/public/basic.ics). 
 
 Note: iCalendar (iCal/.ics) format is supported by most calendar software, including Outlook, Thunderbird.