More detailed README?

[geerlingguy]

Very interested in this project; would you consider adding some more details to the README, for example:

• If this is based on Ansible Operator, mention that and link to it (I presume it is?)
• Details on how to customize it and usage instructions

[thom8]

Added a little more info -- https://github.com/thom8/drupal-operator/blob/master/README.md

Still not as stable as I'd like but once it is I'll circle back round to document the variables for customisation.