Keyboard: add Wavelet (#3739)

* Add Wavelet keyboard

* Fix build error for keyboards w/o Planck MIT layout

* Add swap hands support

keyboards/wavelet/wavelet.c

@@ -0,0 +1,29 @@
+#include "wavelet.h"
+
+void matrix_init_kb(void) {
+
+    // // green led on
+    // DDRD |= (1<<5);
+    // PORTD &= ~(1<<5);
+
+    // // orange led on
+    // DDRB |= (1<<0);
+    // PORTB &= ~(1<<0);
+
+	matrix_init_user();
+};
+
+#ifdef SWAP_HANDS_ENABLE
+__attribute__ ((weak))
+const keypos_t hand_swap_config[MATRIX_ROWS][MATRIX_COLS] = {
+
+  {{5, 4}, {4, 4}, {3, 4}, {2, 4}, {1, 4}, {0, 4}},
+  {{5, 5}, {4, 5}, {3, 5}, {2, 5}, {1, 5}, {0, 5}},
+  {{5, 6}, {4, 6}, {3, 6}, {2, 6}, {1, 6}, {0, 6}},
+  {{5, 7}, {4, 7}, {3, 7}, {2, 7}, {1, 7}, {0, 7}},
+  {{0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}, {5, 0}},
+  {{0, 1}, {1, 1}, {2, 1}, {3, 1}, {4, 1}, {5, 1}},
+  {{0, 2}, {1, 2}, {2, 2}, {3, 2}, {4, 2}, {5, 2}},
+  {{0, 3}, {1, 3}, {2, 3}, {3, 3}, {4, 3}, {5, 3}},
+};
+#endif