Have tooling to support meeting scheduling for Djangonauts

[sarahboyce]

We have had consistent feedback that meeting scheduling is very hard
We try to gather availabilities during applications to find folks who will have a good overlap with their Navigators especially (as this is the largest meeting) and confirm these but timezones are tricky and Navigators still find it hard to schedule a meeting
Being able to already collect the regularly available times for Djangonauts during the week that we can share with Navigators/Captains that they can then chose from would make the "rocket launch" of the session much smoother
The right tooling can also help us with assessing applicants and team matching

(cc @ontowhee @tim-schilling )