Add default ortho_1x1 layout (#13118)

layouts/default/ortho_1x1/default_ortho_1x1/keymap.c

@@ -0,0 +1,12 @@
+#include QMK_KEYBOARD_H
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    /*
+     * ┌───┐
+     * │ A │
+     * └───┘
+     */
+    [0] = LAYOUT_ortho_1x1(
+        KC_A
+    )
+};