Moved definition of MAX_LAYERS next to LayerState declaration

Also redefined it in terms of the size of LayerState

src/layers.cpp

@@ -3,6 +3,11 @@
 static uint8_t DefaultLayer;
 static uint32_t LayerState;
 
+// The maximum number of layers allowed. `LayerState`, which stores
+// the on/off status of the layers in a bitfield has only 32 bits, and
+// that should be enough for almost any layout.
+#define MAX_LAYERS sizeof(LayerState) * 8;
+
 uint8_t Layer_::highestLayer;
 Key Layer_::liveCompositeKeymap[ROWS][COLS];
 uint8_t Layer_::activeLayers[ROWS][COLS];

src/layers.h

@@ -11,11 +11,6 @@
   const Key keymaps[][ROWS][COLS] PROGMEM = { layers };		\
   uint8_t layer_count = sizeof(keymaps) / sizeof(*keymaps);
 
-// The maximum number of layers allowed. `LayerState`, which stores
-// the on/off status of the layers in a bitfield has only 32 bits, and
-// that should be enough for almost any layout.
-#define MAX_LAYERS 32
-
 class Layer_ {
  public:
   Layer_(void);