Add "Smart Period started intent" to API

From Konst on 2015/01/08 20:24:34 +0000

Please add a “Smart Period started” intent to your API! I see you already have “Sleep tracking started”, “Alarm triggered” and others, but I think It would be better if the other program(ex. Tasker) will know in advance that I would soon wake up - And Tasker launches coffee machine, for example :wink:
Thank you!

Copied from original feature request: