add comprehensive documentation (core, develop, functions, technical guide, contributor guide)

[MickLesk]

✍️ Description

Introduces multiple new documentation files covering system defaults, development/debugging modes, exit codes, technical references, API usage, contribution guidelines, container and install guides, and function library references. This provides detailed guidance for users and contributors on configuration, troubleshooting, development workflows, and best practices.

As next Step - we remove the .github/CONTRI* Files and modify the Readme for Contributor.

✅ Prerequisites (X in brackets)

• Self-review completed – Code follows project standards.
• Tested thoroughly – Changes work as expected.
• No security risks – No hardcoded secrets, unnecessary privilege escalations, or permission issues.

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🛠️ Type of Change (X in brackets)

• 🐞 Bug fix – Resolves an issue without breaking functionality.
• ✨ New feature – Adds new, non-breaking functionality.
• 💥 Breaking change – Alters existing functionality in a way that may require updates.
• 🆕 New script – A fully functional and tested script or script set.
• 🌍 Website update – Changes to website-related JSON files or metadata.
• 🔧 Refactoring / Code Cleanup – Improves readability or maintainability without changing functionality.
• 📝 Documentation update – Changes to README, AppName.md, CONTRIBUTING.md, or other docs.