feat: Remove outdated testing documentation and add comprehensive development and feature guides

- Deleted `TESTING_SETUP.md` and `TEST_UPDATES_SUMMARY.md` as they were outdated.
- Introduced `CHANGELOG.md` to document notable changes and version history.
- Added `DEVELOPMENT.md` for detailed development setup, testing framework, and debugging guidance.
- Created `FEATURES.md` to outline core features and functionalities of TheChart.
- Established `README.md` as a centralized documentation index for users and developers.

docs/README.md

@@ -0,0 +1,76 @@
+# TheChart Documentation
+
+Welcome to TheChart documentation! This guide will help you navigate the available documentation.
+
+## 📖 Documentation Index
+
+### For Users
+- **[README.md](../README.md)** - Quick start guide and installation
+- **[Features Guide](FEATURES.md)** - Complete feature documentation
+  - Modular Medicine System
+  - Advanced Dose Tracking
+  - Graph Visualizations
+  - Data Management
+
+### For Developers
+- **[Development Guide](DEVELOPMENT.md)** - Development setup and testing
+  - Testing Framework (93% coverage)
+  - Code Quality Tools
+  - Architecture Overview
+  - Debugging Guide
+
+### Project History
+- **[Changelog](CHANGELOG.md)** - Version history and feature evolution
+  - Recent updates and improvements
+  - Migration notes
+  - Future roadmap
+
+## 🚀 Quick Navigation
+
+### Getting Started
+1. **Installation**: See [README.md - Installation](../README.md#installation)
+2. **First Run**: See [README.md - Running the Application](../README.md#running-the-application)
+3. **Key Features**: See [FEATURES.md](FEATURES.md)
+
+### Development
+1. **Setup**: See [DEVELOPMENT.md - Development Environment Setup](DEVELOPMENT.md#development-environment-setup)
+2. **Testing**: See [DEVELOPMENT.md - Testing Framework](DEVELOPMENT.md#testing-framework)
+3. **Contributing**: See [DEVELOPMENT.md - Development Workflow](DEVELOPMENT.md#development-workflow)
+
+### Advanced Usage
+1. **Medicine Management**: See [FEATURES.md - Modular Medicine System](FEATURES.md#-modular-medicine-system)
+2. **Dose Tracking**: See [FEATURES.md - Advanced Dose Tracking](FEATURES.md#-advanced-dose-tracking)
+3. **Visualizations**: See [FEATURES.md - Enhanced Graph Visualization](FEATURES.md#-enhanced-graph-visualization)
+
+## 📋 Documentation Standards
+
+All documentation follows these principles:
+- **Clear Structure**: Hierarchical organization with clear headings
+- **Practical Examples**: Code snippets and usage examples
+- **Up-to-date**: Synchronized with current codebase
+- **Comprehensive**: Covers all major features and workflows
+- **Cross-referenced**: Links between related sections
+
+## 🔍 Finding Information
+
+### By Topic
+- **Installation & Setup** → [README.md](../README.md)
+- **Feature Usage** → [FEATURES.md](FEATURES.md)
+- **Development** → [DEVELOPMENT.md](DEVELOPMENT.md)
+- **Version History** → [CHANGELOG.md](CHANGELOG.md)
+
+### By User Type
+- **End Users** → Start with [README.md](../README.md), then [FEATURES.md](FEATURES.md)
+- **Developers** → [DEVELOPMENT.md](DEVELOPMENT.md) and [CHANGELOG.md](CHANGELOG.md)
+- **Contributors** → All documentation, especially [DEVELOPMENT.md](DEVELOPMENT.md)
+
+### By Task
+- **Install TheChart** → [README.md - Installation](../README.md#installation)
+- **Add New Medicine** → [FEATURES.md - Modular Medicine System](FEATURES.md#-modular-medicine-system)
+- **Track Doses** → [FEATURES.md - Advanced Dose Tracking](FEATURES.md#-advanced-dose-tracking)
+- **Run Tests** → [DEVELOPMENT.md - Testing Framework](DEVELOPMENT.md#testing-framework)
+- **Deploy Application** → [README.md - Deployment](../README.md#deployment)
+
+---
+
+**Need help?** Check the troubleshooting sections in [README.md](../README.md#troubleshooting) and [DEVELOPMENT.md](DEVELOPMENT.md#debugging-and-troubleshooting).