Add a new "Guide To Monitor" with walkthroughs of the new editor.
Updates from review of monitoring guide.
Updates to create monitor docs based on feedback.
Convert monitor guide to markdown.
More updates of monitoring guide.

- Add info about API to FAQ.
- Add info about notifying users outside of datadog.
Add monitor API docs.

- Document different monitor types.
- Document all available options for monitors, including downtime
  and scoped muting.
Fix up API endpoints for monitors.
Merge branch 'conor/guide-to-monitoring' into staging
Merge branch 'conor/monitor-api' into staging
Link to guide to monitoring in nav.
Merge branch 'conor/guide-to-monitoring' into staging
Have jenkins care of environment-specific deployment.
Merge branch 'use_jenkins_s3' into staging
Revert "Have jenkins care of environment-specific deployment."

This reverts commit 7a55f6c2a62aeb67db68f115c8a9b8a4ae74d3b6.
Fix typo in guide to monitoring.
Merge branch 'conor/guide-to-monitoring' into staging
Merge remote-tracking branch 'upstream/staging' into ja-jp