Documentation update: rasa init

[kevinthenet]

Description of Problem:

rasa init documentation is missing the newly added tests/ directory to the resulting directory tree (shown below):

├── actions.py
├── config.yml
├── credentials.yml
├── data
│   ├── nlu.md
│   └── stories.md
├── domain.yml
├── endpoints.yml
├── __init__.py
├── models
│   └── <timestamp>.tar.gz.tar.gz
└── tests
    └── conversation_tests.md

Overview of the Solution:

Update documentation to show up-to-date directory tree.

Examples (if relevant):

Blockers (if relevant):

Definition of Done:

• update documentation to match current rasa init behavior
• update changelog

[sara-tagger]

Thanks for submitting this feature request 🚀 @akelad will get back to you about it soon! ✨