[Keyboard] Add MachKeyboards Mach3 (#14791)

Co-authored-by: Ryan <fauxpark@gmail.com>

keyboards/machkeyboards/mach3/config.h

@@ -0,0 +1,45 @@
+/* Copyright 2021 Mach Keyboards
+
+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       0x4D41
+#define PRODUCT_ID      0x4D33
+#define DEVICE_VER      0x0001
+#define MANUFACTURER    MachKeyboard
+#define PRODUCT         Mach33
+
+/* key matrix size */
+#define MATRIX_ROWS 3
+#define MATRIX_COLS 3
+
+/* key pins */
+#define MATRIX_ROW_PINS { D1, D0, D4 }
+#define MATRIX_COL_PINS { E6, B4, B5 }
+
+/* COL2ROW, ROW2COL*/
+#define DIODE_DIRECTION COL2ROW
+
+/* backlight */
+#define BACKLIGHT_PIN B6
+#define BACKLIGHT_BREATHING
+#define BACKLIGHT_LEVELS 5
+
+/* debounce */
+#define DEBOUNCE 5