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/config.h

@@ -38,6 +38,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { F0, F1, E6, C7, C6, B7, D4, B1, B0, B5, B4, D7, D6, B3 }
 #define UNUSED_PINS
 
+#define BACKLIGHT_PIN B6
+
 /* COL2ROW or ROW2COL */
 #define DIODE_DIRECTION COL2ROW