Keyboard: Add Prime_EXL prototype to 'handwired' (#3932)

* initial commit

* Update readme.md

* Update keymap.c

added comment for description of function to control LED as layer indicator

* corrected formatting as requested.

* format for configurator

* corrected info.json to propertly reflect layout in Configurator

* updated layouts to reflect physical keyboard

keyboards/handwired/prime_exl/config.h

@@ -0,0 +1,56 @@
+/*
+Copyright 2018 Holten Campbell
+
+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/>.
+*/
+
+#pragma once
+
+#include "config_common.h"
+
+/* USB Device descriptor parameter */
+#define VENDOR_ID       0xFEED
+#define PRODUCT_ID      0x4024
+#define DEVICE_VER      0x0001
+#define MANUFACTURER    PrimeKB
+#define PRODUCT         Prime_EXL
+#define DESCRIPTION     Ergo
+
+/* key matrix size */
+#define MATRIX_ROWS 10
+#define MATRIX_COLS 9
+
+/* Keyboard Matrix Assignments */
+#define MATRIX_ROW_PINS { B1, E6, D5, D6, B4, D7, D4, F1, F0, B0 }
+#define MATRIX_COL_PINS { D0, B3, B2, D1, D2, D3, F7, F6, F5 }
+#define UNUSED_PINS
+
+/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+#define DIODE_DIRECTION COL2ROW
+
+#define BACKLIGHT_PIN B7
+#define BACKLIGHT_LEVELS 5
+
+/* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
+#define DEBOUNCING_DELAY 5
+
+/* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
+#define LOCKING_SUPPORT_ENABLE
+/* Locking resynchronize hack */
+#define LOCKING_RESYNC_ENABLE
+
+/* key combination for magic key command */
+#define IS_COMMAND() ( \
+    keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)) \
+)