[Feature Request] Document Ctrl+G system editor shortcut in documentation

Bug Description

I discovered the Ctrl+G shortcut by accident - please update your docs to share this awesome feature with others :D (thanks for adding this). I was already occasionally writing my long-prompts in a file but having this quick access directly makes this more conveieniet.

Environment Info

• Platform: darwin
• Terminal: tmux
• Version: 2.0.24
• Feedback ID:

Your current docs do not indicate that this is available: https://docs.claude.com/en/docs/claude-code/interactive-mode#general-controls