added example code for all layer keys

docs/layers.md

@@ -22,3 +22,94 @@ keyboard.modules.append(Layers())
 ## Custom HoldTap Behavior
 `KC.TT` and `KC.LT` use the same heuristic to determine taps and holds as
 ModTap. Check out the [ModTap doc](modtap.md) to find out more.
+
+## Example Code
+For the below examples, assume an example 3x3 keyboard with 3 layers as follows:
+
+```python
+#EXAMPLE = example code
+
+keyboard.keymap = [
+	# Base layer
+	[
+		KC.A,	KC.B,	KC.C,
+		KC.D,	KC.E,	KC.F,
+		KC.G,	KC.H,	EXAMPLE,
+	],
+
+	# Arrow layer
+	[
+		KC.NO,	KC.UP,	KC.NO,	
+		KC.LEFT,KC.DOWN,KC.RGHT,
+		KC.NO,	KC.NO,	KC.TRNS,	
+	],
+
+	# Function Layer
+	[
+		KC.F1,	KC.F2,	KC.F3,
+		KC.F4,	KC.F5,	KC.F6,
+		KC.NO,	KC.NO,	KC.TRNS,	
+	],
+]
+```
+
+### KC.DF()
+Changes the default layer until the keyboard is powered off. The following would change the above keymap 
+so that the `EXAMPLE` key would set the arrow layer to be default until the kyeboard is powered off.
+
+```python
+EXAMPLE = KC.DF(1)
+```
+
+### KC.MO()
+Activates specified layer while held, similar to how the `Fn` key works on a normal keyboard. The following 
+would activate the Function layer while held.
+
+```python
+EXAMPLE = KC.MO(2)
+```
+
+### KC.LM()
+Activates the specified layer with the specified modifier key active, which can be nicer than holding down 
+multiple keys. The following example activates the Function layer with the `RALT` (right Alt) key active, too.
+
+```python
+EXAMPLE = KC.LM(2, KC.RALT)
+```
+
+### KC.LT()
+Activates the specified layer when held but passes the specified keycode when tapped. The following would 
+activate the Arrow layer when held but send an "i" when tapped.
+
+```python
+EXAMPLE = KC.LT(1, KC.I)
+```
+
+### KC.TG()
+Toggles the specified layer on/off when tapped. Other active layers below the toggled layer in the stack 
+may be applicable if the toggled layer has `KC.TRNS` in the same position. The following would toggle the 
+Arrow layer on/off when tapped (note the `KC.TRNS` in the bottom-right position of the Arrow layer allows 
+the `EXAMPLE` key to be pressed on the base layer even when the Arrow layer is active).
+
+```python
+EXAMPLE = KC.TG(1)
+```
+
+### KC.TO()
+Toggles the specified layer _and deactivates all other layers._ *NOTE:* be careful using this keycode! If 
+you don't have another layer switch on the toggled layer, the only way to return to the base layer is to 
+power-cycle the keyboard. The following would turn the keyboard into a navigation pad with 5 useless keys 
+until it was restarted by activating the Arrow layer and deactivating the base layer.
+
+```python
+EXAMPLE = KC.TO(1)
+```
+
+### KC.TT()
+Momentarily switches to the specified layer when held or toggles that same layer when tapped. The following 
+would momentarily activate the Function layer when held or toggle that layer when tapped (note that the layer 
+can be toggled back thanks to the `KC.TRNS` on the Function layer, similar to the `KC.TG()` example above).
+
+```python
+EXAMPLE = KC.TT(2)
+```