examples/Keyboardio/Atreus: Fix the QWERTY layer & macro mess

On the `Upper` layer we have a key that takes us back to the QWERTY layer. That
key appeared as `M(QWERTY)` on the keymap, while `QWERTY` was the layer name,
and `LAYER_QWERTY` was supposed to be the macro name. In the macro itself, we
used `Layer.move(LAYER_QWERTY)` - the macro name instead of the layer name.

In practice, this didn't matter, because both ended up resolving to `0`, but the
code did not reflect intention, and was confusing for anyone trying to
understand what's going on.

Signed-off-by: Gergely Nagy <algernon@keyboard.io>

examples/Devices/Keyboardio/Atreus/Atreus.ino

@@ -33,7 +33,7 @@
 #define TG(n) LockLayer(n)
 
 enum {
-  LAYER_QWERTY
+  MACRO_QWERTY
 };
 
 #define Key_Exclamation LSHIFT(Key_1)
@@ -82,15 +82,15 @@ KEYMAPS(
 
   [UPPER] = KEYMAP_STACKED
   (
-       Key_Insert ,Key_Home                 ,Key_UpArrow   ,Key_End        ,Key_PageUp
-      ,Key_Delete ,Key_LeftArrow            ,Key_DownArrow ,Key_RightArrow ,Key_PageDown
-      ,XXX        ,Consumer_VolumeIncrement ,XXX           ,XXX            ,___ ,___
-      ,M(QWERTY)  ,Consumer_VolumeDecrement ,___           ,___            ,___ ,___
-
-                ,Key_UpArrow   ,Key_F7 ,Key_F8          ,Key_F9         ,Key_F10
-                ,Key_DownArrow ,Key_F4 ,Key_F5          ,Key_F6         ,Key_F11
-      ,___      ,XXX           ,Key_F1 ,Key_F2          ,Key_F3         ,Key_F12
-      ,___      ,___           ,M(QWERTY)  ,Key_PrintScreen ,Key_ScrollLock ,Consumer_PlaySlashPause
+       Key_Insert      ,Key_Home                 ,Key_UpArrow   ,Key_End        ,Key_PageUp
+      ,Key_Delete      ,Key_LeftArrow            ,Key_DownArrow ,Key_RightArrow ,Key_PageDown
+      ,XXX             ,Consumer_VolumeIncrement ,XXX           ,XXX            ,___ ,___
+      ,M(MACRO_QWERTY) ,Consumer_VolumeDecrement ,___           ,___            ,___ ,___
+
+                ,Key_UpArrow   ,Key_F7          ,Key_F8          ,Key_F9         ,Key_F10
+                ,Key_DownArrow ,Key_F4          ,Key_F5          ,Key_F6         ,Key_F11
+      ,___      ,XXX           ,Key_F1          ,Key_F2          ,Key_F3         ,Key_F12
+      ,___      ,___           ,M(MACRO_QWERTY) ,Key_PrintScreen ,Key_ScrollLock ,Consumer_PlaySlashPause
    )
 )
 /* *INDENT-ON* */
@@ -110,8 +110,8 @@ KALEIDOSCOPE_INIT_PLUGINS(
 
 const macro_t *macroAction(uint8_t macroIndex, uint8_t keyState) {
   switch (macroIndex) {
-  case QWERTY:
-    Layer.move(LAYER_QWERTY);
+  case MACRO_QWERTY:
+    Layer.move(QWERTY);
     break;
   default:
     break;