Include link to public events calendar

[ApolloZhu]

Possible options

• Link: https://calendar.google.com/calendar/embed?src=c_7m9ae8ao055nnrln07mfbfedfs%40group.calendar.google.com&ctz=America%2FLos_Angeles
• Embed (more customizations on Google Calendar)

<iframe src="https://calendar.google.com/calendar/embed?src=c_7m9ae8ao055nnrln07mfbfedfs%40group.calendar.google.com&ctz=America%2FLos_Angeles" style="border: 0" width="800" height="600" frameborder="0" scrolling="no"></iframe>

• iCal: https://calendar.google.com/calendar/ical/c_7m9ae8ao055nnrln07mfbfedfs%40group.calendar.google.com/public/basic.ics

[ApolloZhu]

Per 2021-09-15 board meeting, replace the #calendar Discord channel, potentially with a Discord bot