Detail where the JSON Schema can be found

[JohnLBevan]

Concourse uses YAML for a number of its pieces. I suspect it uses a JSON Schema for this, but I've been unable to find one, though the documentation does seem to be a human-worded version of a JSON Schema.

Do you know if such a schema is published / available somewhere? If so, could this be added to the docs?

Side note: I've created a quick and dirty one here for tasks, based on the above documentation, should anyone else be looking for the same.