📋 Improve onboarding documentation for new contributors

[enioxt]

Problem

New contributors face multiple barriers when trying to run EGOS Inteligência locally:

1. API keys are confusing — no clear instructions on where to get each key
2. No IDE-specific guides — Windsurf and Antigravity users need help
3. Setup assumes Docker knowledge — beginners get lost
4. No video/visual walkthrough
5. Contributing guide is generic — doesn't explain the project structure

What We Need

• Step-by-step video or GIF walkthrough of local setup
• Expand .env.example with inline comments explaining each key + link to obtain
• Create docs/GETTING_STARTED.md with visual guide
• Add troubleshooting section (common Docker/Neo4j errors)
• Test the setup on a clean machine (Ubuntu 22.04)
• Add architecture diagram (Mermaid or image)

Current State

README was updated (2026-03-03) with API key table and IDE instructions. See docs/SYSTEM_CAPABILITIES_2026-03.md for full system map.

Good First Issue

This is perfect for documentation contributors who want to help without coding!