Task/add modernization agent (#490)

* Adding modernization agent

This is a Modernization Agent. It will first understand the repository it will work on, then create comprehensive suggestions by asking the developer at each main step, like choosing the target tech stack or architecture.

* Update README.agents.md for modernization agent

* Update README.agents.md

* Fix modernization.agent.md yaml format

* Revise modernization agent documentation and tools

Updated agent documentation to reflect changes in model name, tools, and workflow details. Enhanced clarity on analysis phases, documentation requirements, and implementation planning.

* Refactor modernization agent documentation

Updated the title and improved formatting for clarity.

* Update Modernization Agent description in README

Author: mehmetalierol