[Keymap] Added Xerpocalypse's layout (#6732)

* Added Xerpocalypse's layout

+ Number row and symbols are switched compared to default TMO50 layout
+ Right-hand spacebar acts as backspace and a hold-layer for layer 2.

* Update keyboards/tmo50/keymaps/xerpocalypse/keymap.c

Removed unnecessary #define

Co-Authored-By: noroadsleft <18669334+noroadsleft@users.noreply.github.com>

* Update keyboards/tmo50/keymaps/xerpocalypse/keymap.c

Changed keymap to use KC_UNDS instead of custom-defined keycode

Co-Authored-By: noroadsleft <18669334+noroadsleft@users.noreply.github.com>

keyboards/tmo50/keymaps/xerpocalypse/keymap.c

@@ -0,0 +1,56 @@
+/* Copyright 2019 funderburker
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include QMK_KEYBOARD_H
+
+#define LT1_SPC     LT(1, KC_SPC)
+#define LT2_SPC     LT(2, KC_BSPC)
+#define TSKMNGR     C(S(KC_ESC))
+#define ALT_TAB     A(KC_TAB)
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+
+  // Default layer
+  [0] = LAYOUT_all(
+		KC_TRNS, KC_TAB,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    KC_Y,    KC_U,    KC_I,    KC_O,   KC_P,    KC_LBRC, KC_RBRC, KC_BSPC,
+		KC_TRNS, KC_LCTL, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_H,    KC_J,    KC_K,    KC_L,   KC_SCLN, KC_QUOT, KC_ENT,
+		KC_TRNS, KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_N,    KC_M,    KC_COMM, KC_DOT, KC_SLSH, KC_RSFT, MO(3),
+		KC_TRNS, 		  KC_LGUI, KC_LALT, LT1_SPC, LT2_SPC, KC_RALT, KC_RCTL
+  ),
+ 
+  // Fn1 layer
+  [1] = LAYOUT_all(
+		KC_GRV,  KC_ESC,  KC_1,    KC_2,    KC_3,    KC_4,    KC_5,    KC_6,    KC_7,    KC_8,    KC_9,    KC_0,    KC_MINS, KC_EQL,  KC_BSPC,
+		C(KC_C), KC_TRNS, KC_EXLM, KC_AT,   KC_HASH, KC_DLR,  KC_PERC, KC_CIRC, KC_AMPR, KC_ASTR, KC_LPRN, KC_RPRN, KC_UNDS, KC_TRNS,
+		C(KC_V), KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_SPC,  KC_TRNS, KC_SPC,  KC_TRNS, KC_TRNS, KC_TRNS, KC_BSLS, KC_TRNS, KC_TRNS,
+		C(KC_X), 		  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS
+  ),
+
+  // Fn2 layer
+  [2] = LAYOUT_all(
+		ALT_TAB, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_DEL,
+		TSKMNGR, KC_TRNS, KC_MUTE, KC_VOLD, KC_VOLU, KC_TRNS, KC_TRNS, KC_LEFT, KC_DOWN, KC_UP  , KC_RGHT, KC_TRNS, KC_TRNS, KC_TRNS,
+		KC_TRNS, KC_TRNS, KC_MPLY, KC_MPRV, KC_MNXT, KC_TRNS, KC_TRNS, KC_PGUP, KC_PGDN, KC_HOME, KC_END,  KC_TRNS, KC_TRNS, KC_TRNS,
+		KC_TRNS, 		  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS
+  ),
+
+  // Fn3 layer
+  [3] = LAYOUT_all(
+        RESET,   KC_F1,   KC_F2,   KC_F3,   KC_F4,   KC_F5,   KC_F6,   KC_F7,  KC_F8,   KC_F9,   KC_F10,  KC_F11,  KC_F12,  KC_TRNS, KC_TRNS,
+		KC_TRNS, KC_CAPS, RGB_TOG, RGB_HUI, RGB_SAI, RGB_VAI, BL_TOGG, BL_INC, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
+		KC_TRNS, KC_TRNS, RGB_MOD, RGB_HUD, RGB_SAD, RGB_VAD, BL_STEP, BL_DEC, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS,
+		KC_TRNS, 		  KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS, KC_TRNS
+  ),
+};