Backlight abstraction and other changes (#439)

* redoes matrix pins, abstracts backlight code for B5,6,7

* slimming down keyboard stuff, backlight breathing implemented

* don't call backlight init when no pin

* cleans up user/kb/quantum calls, keyboard files

* fix pvc atomic

* replaces CHANNEL with correct var in breathing

* removes .hexs, updates readmes, updates template

* cleans-up clueboards, readmes to lowercase

* updates readme

keyboards/satan/satan.h

@@ -1,10 +1,7 @@
 #ifndef SATAN_H
 #define SATAN_H
 
-#include "matrix.h"
-#include "keymap.h"
-#include <stddef.h>
-#include "action_util.h"
+#include "quantum.h"
 
 /* Clueboard matrix layout
    * ,-----------------------------------------------------------.