Fix typos and improve documentation clarity

[Davidiusdadi]

Summary

This PR fixes multiple typos throughout the README and .env.example file, and significantly improves the documentation structure and clarity, particularly in the setup and usage instructions.

Key Changes

Documentation Fixes

• Fixed typo: "Obsidan" → "Obsidian" (4 occurrences)
• Fixed typo: "fist" → "first" in "magic first word node"
• Fixed typo: "promptes" → "prompts"
• Fixed typo: "anyting" → "anything"
• Improved grammar: "basic understanding javascript-programming" → "basic understanding of javascript programming"
• Fixed typo: "and identity" → "an identity" (2 occurrences)

Setup Instructions Restructuring

• Reorganized "how to run" section with clear subsections:
  • Initial Setup - Step-by-step installation guide
  • Running Examples - Organized by feature category
• Added helpful notes about optional dependencies and API keys
• Clarified that LLM features are optional and not required for basic functionality
• Added visual indicators (✅ and 🔑) to distinguish examples by requirements

Example Path Updates

• Updated all example canvas paths from tutorial/ to feature-tour/ structure
• Reorganized examples into logical feature categories:
  • feature-tour/1-arrow-propagation/
  • feature-tour/2-flow-control/
  • feature-tour/3-canvas-signals/
  • feature-tour/4-canvas-overload/

Environment Configuration

• Updated .env.example with corrected provider names:
  • Fixed "ANTROPIC" → "ANTHROPIC_API_KEY"
  • Updated model name to current version: claude-3-5-haiku-20241022
  • Corrected API URL: api.anthropic.com
• Improved comment clarity for optional configuration

Notable Details

• All changes are non-functional documentation improvements
• The restructured examples section now clearly separates features that require API keys from those that don't
• Installation instructions are now more beginner-friendly with better formatting and clearer steps

https://claude.ai/code/session_01871jyJg9rKfR4QAooAyHmU