docs: README's Steam Machine part lists its features, HDMI-CEC included

README.md

@@ -36,9 +36,11 @@ Steam Machine.
 
 ## Steam Machine
 
-On a Valve Steam Machine **HDMI-CEC** is ticked by default, as on SteamOS,
-and the menu has two more items:
+What Steamify can do on a Valve Steam Machine:
 
+- **HDMI-CEC** - ticked by default here, as on SteamOS: use Steam with your
+  TV's remote, and the TV turns on and off with the Steam Machine
+  ([details](TECHNICAL.md#hdmi-cec)).
 - **Steam Machine support** - the front **LED bar** works, Steam's
   **hardware settings** (fan, performance) work, and the power
   button puts it to sleep like a console.