Add new automation recipes and integration examples documentation

[bohdanaims]

📋 Task

Expand the automation/ directory with practical, working automation recipes and integration examples that help users build real workflows faster.

✅ Acceptance Criteria

• Add at minimum 3 new automation recipe files under automation/
• Each recipe must include: overview, prerequisites, step-by-step setup, code example, and troubleshooting section
• All code examples must be complete and tested — no pseudocode
• Add comments to explain complex logic within examples
• Use realistic placeholder data (no real API keys or credentials)
• Verify all links to related integrations and API endpoints are valid

📁 Target Directory

automation/
├── recipes/
│   ├── slack-task-notifications.md
│   ├── github-pr-to-project.md
│   └── stripe-payment-onboarding.md

🔗 References

• Automations: The Execution Pillar
• Full List of Integrations
• Contributing Guide

🏷️ Labels

documentation · enhancement · help wanted