Getting-started tutorial

[simontaurus]

Write getting-started tutorial for OO-LD. Cover installation, first schema, code generation, basic usage.

Acceptance Criteria

• Getting-started tutorial written
• Covers installation and setup
• Covers first OO-LD schema creation
• Covers code generation workflow

[simontaurus]

Improvements:

• @context could be introduced earlier
• user needs to understand JSON-SCHEMA and JSON-LD first - summarize at least the most important aspects
• understand user groups, provide different entry points