Docs for Rules Manager API

[heidmotron]

As of release 1.4.0, we've included a new API endpoints for managing recording rules and alerts via the new Rules Manager API but haven't documented how admins and developers building integrations with the Metric Store can take advantage of it.

• HTTP Methods and expected payload for each point
• Potential errors

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this. Unfortunately, the Pivotal Tracker project is private so you may be unable to view the contents of the story.

The labels on this github issue will be updated when the story is started.