"Add to GCal" reminder / link / button near "Save" button

[Alys]

When you create a commitment and immediately review or adjust its date-time settings, it's too easy to forget to click "Add to GCal" when you've finished. Possible solutions:

• Duplicate the "Add to GCal" link under the save button. Disadvantage: you might click it before saving in which case your changes aren't applied to the calendar event. After saving, the save button area is now off-screen so a GCal link at the bottom of the form is then pointless.
• Just have a reminder saying "Don't forget to add to GCal!". Probably not that useful and annoying if you don't use Google services.
• Have a "Save" button as now and next to it a "Save and Add to GCal" button that does both actions at once (so you choose which button you click on after your edits are finished).
• Have an option to automatically add all commitments to the calendar? I'd use that, but I suspect some people would want to choose which ones they add so it wouldn't help them.
• Have some visible marker on commitments that have not been added to the calendar? Annoying for people who never use the GCal integration.
• Something else?

This is probably not worth putting much thought into until after the React port is finished.

(Suggestion: add "Wait for React" label.)