Include a diagram showing what the RxCy coordinates mean

README.md

@@ -58,6 +58,7 @@ state upon which to trigger the custom action. Both of these are bit fields,
 each bit set tells the extension that the key with that index must be held for
 the action to trigger. It is recommended to use the `RxCy` macros of the core
 `KaleidoscopeFirmware`, and *or* them together to form a bitfield.
+See below for a diagram showing how the `RxCy` coordinates coorespond to your keyboad.
 
 The combo list **must** end with an element containing zero values for both the
 left and the right halves.
@@ -103,4 +104,8 @@ the overrideable `magicComboActions` function:
 Starting from the [example][plugin:example] is the recommended way of getting
 started with the plugin.
 
+`RxCy` coordinates for a Model01:
+
+![rxcy layout][./docs/rc_layout.png]
+
  [plugin:example]: https://github.com/keyboardio/Kaleidoscope-MagicCombo/blob/master/examples/MagicCombo/MagicCombo.ino