Documentation needed for workflow expression language

[dustinblack]

Please describe what you would like to see in this project

There is only very light coverage of the expression language currently in the docs. We need to make sure this is clearly documented and easy to consume with examples.

[jaredoconnell]

The documentation should specify:

• Where you can use expressions
• How to enable an expression instead of it being interpreted as a literal
• Functions (once implemented)
• Comparisons (once implemented)
• Math (if/once implemented)
• Some details on the data structure the paths are accessing, like how to access step output, or input.

Does this help? https://arcalot.io/arcaflow/workflows/expressions/

[jaredoconnell]

Good start. That's all that's necessary right now. I will keep this open until I document the new features once they're out.