Add user guide for Procedural Scheduling to aerie-docs

[dandelany]

The Scheduling section of the Aerie docs should be updated to explain our new Procedural Scheduling feature - maybe this section should be split into two ie. "Scheduling EDSL" and "Procedural Scheduling". Things that should be covered:

• General explanation of the workflow
• Links to API docs (#1457) and starter repo (#1453)
• Examples demonstrating the most important parts of API
• Building and uploading procedures
• Updating existing procedures & versioning
• Adding procedures to scheduling spec, details about priority/run order
• Passing parameters into procedures
• Running procedures, how to view logs
• How to run locally with debugger - if this is meant to be a user-facing feature?

We should also update the Scheduling section of the GraphQL API docs to reflect any new changes.

[dandelany]

@JoelCourtney is working on some more new user tutorial content for this section of the docs