Request: Documentation for MCP Server Configuration and Setup

### Checks

- [x] I have searched [github.com/aws/amazon-q-developer-cli/issues](https://github.com/aws/amazon-q-developer-cli/issues?q=) and there are no duplicates of my issue
- [x] I have run `q doctor` in the affected terminal session
- [x] I have run `q restart` and replicated the issue again

### Operating system

macOS 26.0.1 (25A362)

### Expected behaviour

Clear documentation should be available explaining how to configure and add MCP servers to Q CLI, including:
- MCP configuration file format and location
- Step-by-step setup instructions for adding new MCP servers
- Examples of common MCP server configurations
- How to configure authentication/credentials for MCP servers
- Troubleshooting guide for MCP server connection issues

### Actual behaviour

The current documentation mentions MCP server support and shows some examples of MCP tool usage in agent configurations, but lacks comprehensive setup instructions. Users cannot easily determine how to add new MCP servers.

### Steps to reproduce

1. User wants to add a new MCP server
2. User searches documentation for MCP setup instructions
3. User finds references to MCP but no complete configuration guide
4. User is unable to proceed with MCP server setup

### Environment

```yaml

```