[Keyboard] Added slash keyboard (#7042)

* feat(slash): added slash keyboard

* fix(slash): fixed typo in readme

* Improvements after review

* disabled debug and print to reduce firmware size

* Fixes after review

* fixed hardware list in readme.md

keyboards/handwired/slash/slash.h

@@ -0,0 +1,36 @@
+/* Copyright 2019 asdftemp
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include "quantum.h"
+
+#define LAYOUT( \
+    k00, k01, k02, k03, k04, k05, k06, k07, k08, k09, k0A, k0B, k0C,    k0D, \
+    k10,    k11, k12, k13, k14, k15, k16, k17, k18, k19, k1A, k1B, k1C, k1D, \
+    k20,     k21, k22, k23, k24, k25, k26, k27, k28, k29, k2A, k2B,     k2C, \
+    k30,      k31, k32, k33, k34, k35, k36, k37, k38, k39, k3A,         k3B, \
+    k40,  k41,  k42,               k43,               k44,  k45,  k46,  k47  \
+) \
+{ \
+    { k00, k02, k04, k06, k08, k0A, k0C, KC_NO }, \
+    { k01, k03, k05, k07, k09, k0B, k0D, KC_NO }, \
+    { k10, k12, k14, k16, k18, k1A, k1C, k45 }, \
+    { k11, k13, k15, k17, k19, k1B, k1D, k44 }, \
+    { k21, k23, k25, k27, k29, k2B, KC_NO, k42 }, \
+    { k20, k22, k24, k26, k28, k2A, k2C, k43 }, \
+    { k31, k33, k35, k37, k39, k3B, k47, k40 }, \
+    { k30, k32, k34, k36, k38, k3A, k46, k41 } \
+}