feat(interactive-docs): generate executable documentation

[gregswindle]

💡 TIP: Select the ↖︎⎾ Preview ⏋ Tab above help read these instructions.

1. Issue type

• Feature: I'm requesting a product enhancement.

2. User story summary

As a consumer or contributor,
I want interactive documentation with RunKit
In order to learn and try using and contributing to generator-community.

3. Acceptance criteria

• 1. Documentation is automatically published whenever changes are merged into master.
• 2. Documentation supports and executes RunKit and Repl.it