Improve git-glimpse onboarding with AI agent prompt and tips

[DeDuckProject]

Summary

Enhanced the README documentation to make git-glimpse easier to integrate and understand, particularly for users new to the project.

Key Changes

• Added a "One-prompt integration" section that provides a quick copy-paste prompt for AI agents (Cursor, Copilot, Claude Code, etc.) to automate the integration process
• Added a helpful tip after the configuration section explaining why starting with auto mode is recommended for first-time setup, clarifying that on-demand mode won't show a demo on the initial PR

Details

These additions address common onboarding friction points:

1. The AI agent prompt reduces manual setup steps by allowing users to delegate integration to their AI assistant
2. The mode selection tip prevents confusion about whether the integration is working correctly, as users starting with on-demand mode won't see any output on their first PR

Both additions are non-intrusive and placed strategically in the Quick start section to guide users at the right moments in their setup journey.

https://claude.ai/code/session_01ReGKL69tPB4CGaLVj4LxVF