chore: revamp the readme with detailed setup +tui docs

[edwinjosechittilappilly]

This pull request makes significant improvements to the README.md documentation for OpenRAG. The changes focus on providing a clearer project overview, restructuring the content for easier navigation, and offering detailed instructions for setup, configuration, development, and deployment. The new README is more comprehensive and user-friendly, helping both new and experienced developers get started quickly and troubleshoot common issues.

Documentation and Project Overview:

• Added a detailed description of OpenRAG, including its features, architecture, and technology stack, making it easier for users to understand the platform's capabilities.
• Introduced a table of contents and reorganized sections for better readability and navigation.

Setup and Development Workflow:

• Provided step-by-step instructions for environment setup, configuration, and starting the platform using Makefile commands, including support for both GPU and CPU-only development.
• Documented development commands, container management, dependency installation, building, testing, debugging, and database operations to streamline the developer workflow.

Configuration and Deployment:

• Expanded environment variable documentation with tables for required and optional variables, including ingestion configuration and service URLs after deployment.
• Added Docker deployment instructions, including standard, CPU-only, and force-rebuild options, as well as troubleshooting tips for common issues and Podman usage on macOS. (F606c05

[Copilot]

Pull Request Overview

This PR completely overhauls the README.md documentation to provide comprehensive setup, configuration, and usage instructions for OpenRAG. The changes transform a basic getting-started guide into a detailed, well-structured documentation that covers all aspects of the platform.

• Added comprehensive project description, table of contents, and structured documentation sections
• Introduced detailed TUI interface documentation with features and navigation instructions
• Expanded configuration documentation with organized tables for required and optional environment variables
• Created a new CONTRIBUTING.md file with extensive development workflow, architecture overview, and debugging guidance

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
README.md	Complete restructure with detailed setup instructions, TUI documentation, configuration tables, and troubleshooting guide
CONTRIBUTING.md	New comprehensive development guide with setup instructions, architecture overview, and debugging procedures

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[Copilot]

The placeholder <repository-url> should be replaced with the actual repository URL. Consider using the actual GitHub/GitLab URL for the OpenRAG repository.

Suggested change

	git clone <repository-url>
	git clone https://github.com/openrag/OpenRAG.git

[Copilot]

The placeholder <repository-url> should be replaced with the actual repository URL. This should match the URL used in the main README.

Suggested change

	git clone <repository-url>
	git clone https://github.com/openrag-org/openrag.git