integrate calendly

[Vandivier]

https://calendly.com/pricing

[Vandivier]

small groups via google calender are working will, so deprioritizing

we may do an official google integration, but that will be after google social sign in
in #151

also the manual approach isn't super difficult atm either, to get signups in google forms and set a recurring mtg outside of the ladderly tool itself. it's potentially sustainable for a long time; we might want to permanently decouple ladderly from mentor calendar tooling...meh idk it would be cool to have working ootb as well

[Vandivier]

google pay to book is another option
https://support.google.com/calendar/answer/13762729

people should also be able to contact the coach
this feature will have more value after a coach book is implemented