[Keyboard] Add Ingrained Keyboard (#15928)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Ryan <fauxpark@gmail.com>
Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>
Co-authored-by: Juan Puerto <jpuerto@psc.edu>
Co-authored-by: jpuerto-psc <68066250+jpuerto-psc@users.noreply.github.com>

keyboards/ingrained/keymaps/default/keymap.c

@@ -0,0 +1,23 @@
+// Copyright 2021 s8erdude (@jpuerto96)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include QMK_KEYBOARD_H
+
+
+// Each layer gets a name for readability, which is then used in the keymap matrix below.
+// The underscores don't mean anything - you can have a layer called STUFF or any other name.
+// Layer names don't all need to be of the same length, obviously, and you can also skip them
+// entirely and just use numbers.
+
+enum layer_names {
+  _BASE,
+};
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+  [_BASE] = LAYOUT_split_3x6_3(
+    KC_ESC,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,          KC_Y,    KC_U,    KC_I,    KC_O,   KC_P,    KC_BSPC,
+    KC_TAB,  KC_A,    KC_S,    KC_D,    KC_F,    KC_G,          KC_H,    KC_J,    KC_K,    KC_L,   KC_SCLN, KC_QUOT,
+    KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,          KC_N,    KC_M,    KC_COMM, KC_DOT, KC_SLSH, KC_RSFT,
+                               KC_LGUI, KC_SPC,  KC_TAB,        KC_BSPC, KC_ENT,  KC_RALT
+  ),
+};