feat: Add example for starting lsmdb server with persistent MVCC store

[ganeshwhere]

This pull request significantly improves the project documentation and adds a runnable server quickstart example. The README.md is rewritten to clarify the project's purpose, architecture, usage modes, and developer benefits, while a new examples/server_quickstart.rs file provides a ready-to-use example for starting and connecting to an lsmdb server.

Documentation improvements:

• Major rewrite of README.md to clarify project goals, architecture, usage scenarios (embedded and server/CLI), developer benefits, and operational details. Adds sections on what technologies are used, how to get started, and current project status.
• Adds explicit references to supporting documentation files and describes the project layout more clearly.

Getting started and usability:

• Adds a new example file examples/server_quickstart.rs that demonstrates how to start a persistent MVCC-backed server in local development mode, including connection instructions for the CLI client.
• Provides clear instructions in the README.md for running the quickstart example and connecting via the CLI.

Contribution and operational guidance:

• Updates contribution guidance to reflect the current areas of need and simplifies the collaboration section.
• Expands on operational and release readiness instructions, including local and CI release gate checks.