CLI: Workflow tooling

[josephjclark]

A common use case is going to be for developers to define their own workflows to test things out locally.

Workflows are actually quite hard to write in JSON. The syntax is fiddly, you need to remember the right key names and structures, and the structure isn't always intuitive.

There are a few ways the CLI might help us out:

• A command to generate a workflow template (with two jobs and a start)
• An interactive command which lets you sketch out a workflow upfront, asking you for each job, what adaptor and credential it wats
• Dedicated documentation for workflows( openfn docs workflow ?)

As a side note, it might be nice to have some way to load env vars into JSON. This is easy if we can load workflows as JS files, but maybe we can use some kind of convention like "user": "$OPENFN_SALESFORCE_USERNAME", which will load $names from the env.

[josephjclark]

Closing as duplicate of #615