📚 DOCS: Add calendar

[choldgraf]

This adds some information about EBP team meetings, and adds links to a calendar with team meeting dates, as well as a HackMD with an agenda template.

It also proposes that we have our first team meeting on Thursday, July 1st at 7am Sydney time.

cc @executablebooks/ebpteam to see if this works for folks!

related to #379

[akhmerov]

Not sure if you find this useful, but here's a script that opens an issue periodically (which is rather trivial), and (less so trivially) creates a new hackmd from template: https://github.com/virtualscienceforum/virtualscienceforum/blob/master/bots/open_org_issue.py

[choldgraf]

OK I've updated the information so that we can use a github issue to track links and upcoming meetings!

@akhmerov ah very cool :-) I do something similar for 2i2c here: https://github.com/2i2c-org/team-compass/blob/main/scripts/post-team-sync.py

[choldgraf]

I think for now, I'll just merge this one in and open up an issue to track the next meeting...we can explore automating the issue creation in the future!