docs: add key bindings and fix ptt key in readme

README.md

@@ -8,6 +8,20 @@ TUI Mumble client with voice support and push-to-talk.
 - Voice transmission with Opus codec
 - Push-to-talk via Kitty keyboard protocol, evdev, or toggle
 - Channel browsing and text chat
+- Chat input history (Up/Down arrow navigation)
+- Self-deafen toggle
+
+## Key Bindings
+
+| Key | Action |
+|-----|--------|
+| `F1` | Toggle self-deafen |
+| `F4` | Push-to-talk (configurable) |
+| `Enter` | Send message |
+| `Up` | Previous sent message (in chat input) |
+| `Down` | Next sent message (in chat input) |
+| `q` | Quit |
+| `Ctrl+C` | Quit |
 
 ## Quick Start
 
@@ -31,7 +45,7 @@ port = 64738
 username = "myname"
 
 [ptt]
-key = "space"
+key = "f4"
 mode = "hold"
 backend = "auto"
 ```