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

layouts/default/ergodox/default_ergodox/keymap.c

@@ -0,0 +1,23 @@
+#include QMK_KEYBOARD_H
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    [0] = LAYOUT_ergodox(
+        KC_GRV,   KC_1,  KC_2,   KC_3,   KC_4,    KC_5,   KC_EQL,
+        KC_TAB,   KC_Q,  KC_W,   KC_E,   KC_R,    KC_T,   KC_EQL,
+        KC_ESC,   KC_A,  KC_S,   KC_D,   KC_F,    KC_G,
+        KC_LSFT, KC_Z,   KC_X,   KC_C,   KC_V,    KC_B,   KC_B,
+        KC_LCTL, KC_F4,  KC_F5,  KC_LGUI,KC_LALT,
+                                                                              KC_C,   KC_V,
+                                                                                      KC_PGUP,
+                                                                    KC_BSPC, KC_BSPC, KC_DEL,
+
+             KC_5,  KC_6,   KC_7,   KC_8,   KC_9,    KC_0,     KC_MINS,
+             KC_Y,  KC_Y,   KC_U,   KC_I,   KC_O,    KC_P,     KC_BSLS,
+                    KC_H,   KC_J,   KC_K,   KC_L,    KC_SCLN,  KC_QUOT,
+             KC_N , KC_N,   KC_M,   KC_COMM,KC_DOT,  KC_SLSH,  KC_RSFT,
+                            KC_LEFT,KC_DOWN,KC_UP,   KC_RIGHT, KC_RGUI,
+             KC_RALT, KC_A,
+             KC_PGDN,
+             KC_RCTL, KC_ENT, KC_SPC
+    ),
+};