Update README.md

Add deprecation notice to README too

Added link to real world example gist

Updating README about the new replacement syntax

Allow multi-line strings, by stripping out newlines, multiple spaces

New feature: rreplacement syntax (replacement from the right)

Remove any trailing comments in commands

Refactoring: Gather duplicated code into _find_outputs()

files() -> file()

Added files() convenience method

Fixing typo. Print commandline output (for now)

No, return to having a few initial comments

Better with even shorter initial code example?

Adding a shorter code example

Updated README.md and workflow_example.py with latest API udpates