chore(ferris/test): visually format keymap (qmk#21851)

... and set all keys to printable characters (as described in the
keymap's readme)

keyboards/ferris/keymaps/test/keymap.c

@@ -7,7 +7,13 @@ void matrix_init_user(void) {
   //debug_mouse=true;
 }
 
+// clang-format off
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
-	[0] = LAYOUT(KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I, KC_O, KC_P, KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K, KC_L, KC_SCLN, KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT, KC_SLSH, KC_P0, DB_TOGG, KC_P2, KC_P3)
+	[0] = LAYOUT(
+        KC_Q, KC_W, KC_E, KC_R, KC_T, KC_Y, KC_U, KC_I,    KC_O,   KC_P,
+        KC_A, KC_S, KC_D, KC_F, KC_G, KC_H, KC_J, KC_K,    KC_L,   KC_SCLN,
+        KC_Z, KC_X, KC_C, KC_V, KC_B, KC_N, KC_M, KC_COMM, KC_DOT, KC_SLSH,
+                          KC_1, KC_2, KC_3, KC_4
+    )
 };
-
+// clang-format on