Add a calendar view on the web site for each member

[marcus-sonestedt]

Is your feature request related to a problem? Please describe. Makes it easy to see one's tasks via integration into other calendar apps, like google.

Describe the solution you'd like

• An user-unique URL endpoint with their calendar (similar to google calendar export)
  • include link to said calendar in emails/sms
• Also, a calendar enpoint for all events, to display on other webpages via calendar widgets

Describe alternatives you've considered Just an invite email when a member is booked on a task, so that they can add it to their own calendar.

Additional context There are some different formats. Investigate and figure out what works best.