Update agent package README

[bhouston]

Update agent package README

The current README for the agent package needs to be updated to better reflect its current capabilities and structure. This PR provides an updated README that:

1. Includes information about all supported LLM providers (Anthropic, OpenAI, Ollama)
2. Documents the Model Context Protocol (MCP) integration
3. Provides more detailed information about the browser automation capabilities
4. Updates the project structure to match the current implementation
5. Adds a usage example
6. Improves the organization and clarity of the documentation

The updated README will make it easier for new users to understand the agent package's capabilities and how to use it effectively.

[bhouston]

Done here: #320