docs: dataflows: Add examples of how to do various things with dataflows

[johnandersen777]

We should add document under the Reference section of the docs that shows how
to do various simple things with dataflows to explain the syntax of the YAML
files / Python equvilant and what those syntaxes do.

We should show how to:

• Modify where the inputs for an operation can come from

  • Override an input so that it gets data from an output of an opreation
    with a different definition.

  • Override an input so that it gets data specific definitions within an
    origin.

    • This
      is a good example of how this syntax can be used.

  • Get inputs from a different origin

    • This
      is a good example of how this syntax can be used.