feat(extensions): most of the extensions implementation, by kdb424

boards/boardsource/3x4/kb.py

@@ -0,0 +1,12 @@
+import board
+
+from kmk.kmk_keyboard import KMKKeyboard as _KMKKeyboard
+from kmk.matrix import DiodeOrientation
+
+
+class KMKKeyboard(_KMKKeyboard):
+    row_pins = (board.P1_15, board.P0_02, board.P0_29)
+    col_pins = (board.P0_09, board.P0_10, board.P1_11, board.P1_13)
+    diode_orientation = DiodeOrientation.COLUMNS
+    i2c = board.I2C
+    powersave_pin = board.P0_13