Update readme instructions, add delete-calendar-event

[WillForan]

• update the readme for google's current oauth cred. request path. Add example code to test configuration.
• add delete for calendar events

[bpoweski]

👍

[takeoutweight]

Hey, this is an ridiculously late response but I want to thank you for putting together this very reasonable PR. We completely dropped the ball on maintaining this library; we're sorry for that and understand how annoying it is to get radio silence after putting work into a PR. We're currently undergoing a review of our open source policies w/ legal and, for what it's worth, should be able to move forward on this and the other open PRs soon.