[Keyboard] add at6 keyboard (#17346)

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

keyboards/atset/at6/keymaps/via/keymap.c

@@ -0,0 +1,39 @@
+/*
+ * 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
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    [0] =
+        LAYOUT( 
+                KC_4 , KC_5 , KC_6, 
+                KC_1 , KC_2 , KC_3
+              ),
+    [1] =
+        LAYOUT(
+                KC_NO , KC_NO, KC_NO,
+                KC_NO , KC_NO, KC_NO
+              ),
+    [2] =
+        LAYOUT(
+                KC_NO , KC_NO, KC_NO,
+                KC_NO , KC_NO, KC_NO
+              ),
+    [3] =
+        LAYOUT(
+                KC_NO , KC_NO, KC_NO,
+                KC_NO , KC_NO, KC_NO
+              )
+};