Missing keybindings reference in TUI

[frankdierolf]

Hola,

We had "show shortcuts" in the previous opencode version and I didn't memorized them. No I miss it. ^^

Or what I wish:

Users can't easily see all available keybindings in the TUI. Would be helpful to have a dialog that shows all keybindings with their descriptions, similar to how models and themes are listed.

Best regards,
Frank ✌️

[rekram1-node]

ill take a look at ur pr