Creates a layouts/ folder for keymaps shared between keyboards (#1609)

* include variables and .h files as pp directives

* start layout compilation

* split ergodoxes up

* don't compile all layouts for everything

* might seg fault

* reset layouts variable

* actually reset layouts

* include rules.mk instead

* remove includes from rules.mk

* update variable setting

* load visualizer from path

* adds some more examples

* adds more layouts

* more boards added

* more boards added

* adds documentation for layouts

* use lowercase names for LAYOUT_

* add layout.json files for each layout

* add community folder, default keymaps for layouts

* touch-up default layouts

* touch-up layouts, some keyboard rules.mk

* update documentation for layouts

* fix up serial/i2c switches

keyboards/satan/rules.mk

@@ -64,3 +64,5 @@ MIDI_ENABLE = no 		# MIDI controls
 AUDIO_ENABLE = no
 UNICODE_ENABLE = no 		# Unicode
 BLUETOOTH_ENABLE = no # Enable Bluetooth with the Adafruit EZ-Key HID
+
+LAYOUTS = 60_ansi 60_iso

keyboards/satan/satan.h

@@ -125,4 +125,7 @@
 void matrix_init_user(void);
 void matrix_scan_user(void);
 
+#define LAYOUT_60_ansi KEYMAP_ANSI
+#define LAYOUT_60_iso KEYMAP
+
 #endif