feat(cli): add Further help section to --help output

[xxchan]

Add epilog with documentation links to --help output:

• Documentation: https://moonshotai.github.io/kimi-cli/
• LLM friendly doc: https://moonshotai.github.io/kimi-cli/llms.txt

Screenshot:

╭─ Commands ───────────────────────────────────────────────────────────────────╮
│ term   Run Toad TUI backed by Kimi CLI ACP server.                           │
│ acp    Run Kimi CLI ACP server.                                              │
│ info   Show version and protocol information.                                │
│ mcp    Manage MCP server configurations.                                     │
╰──────────────────────────────────────────────────────────────────────────────╯
                                                                                
 Further help:   Documentation:     https://moonshotai.github.io/kimi-cli/      
 LLM friendly doc:  https://moonshotai.github.io/kimi-cli/llms.txt              

[Copilot]

Pull request overview

This PR enhances the CLI user experience by adding a "Further help" section to the --help output, providing quick access to documentation resources.

Changes:

• Added an epilog parameter to the Typer CLI configuration with links to the main documentation and LLM-friendly documentation index

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