Hygen setup

[akrigline]

This adds hygen generators to react-gantry. I've created 4 generators in this Pull Request:

• New Component (either functional or class based)
• New Container (either functional or class based)
• New Duck (based on our lightly modified duck file structure)
• New Action for Duck (Injects snippets into each file necessary to create a new action for a specified duck.

To Test: Pull this and have a look through the Readme's Hygen section.

Try out each of the commands and see if the generated files look correct. There are a few lint errors that will happen and some tests will break with just a newly generated file. These are meant to be starting points and will need to be edited before they work again.

This Solves #13.

[akrigline]

@stuarttannehill-rp Done. Added a note in readme about that.