Keyboard: Add 30wer config and keymap (#4386)

* Preliminary 30wer firmware. Not tested on real board yet.

* Added a layer to default 30wer keymap.

* Wrote readme for 30wer.

* Added 30wer info.json.

keyboards/30wer/config.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include "config_common.h"
+
+/* USB Device descriptor parameter */
+#define VENDOR_ID       0x1234
+#define PRODUCT_ID      0x5678
+#define DEVICE_VER      0x0000
+#define MANUFACTURER    8o7wer
+#define PRODUCT         30wer
+#define DESCRIPTION     Gherkin style construction 30% staggered pcb kit
+
+/* key matrix size */
+#define MATRIX_ROWS 3
+#define MATRIX_COLS 13
+
+/* pcb default pin-out */
+#define MATRIX_ROW_PINS { E6, B4, B5 }
+#define MATRIX_COL_PINS { F4, F5, F6, F7, B1, B3, B2, B6, D1, D0, D4, C6, D7 }
+#define UNUSED_PINS
+
+/* COL2ROW or ROW2COL */
+#define DIODE_DIRECTION COL2ROW
+
+/* key combination for command */
+#define IS_COMMAND() ( \
+    keyboard_report->mods == (MOD_BIT(KC_LSHIFT) | MOD_BIT(KC_RSHIFT)) \
+)
+
+/* prevent stuck modifiers */
+#define PREVENT_STUCK_MODIFIERS