feat(keebwerk): added VIA support keymap for keebwerk nano slider (#16761)

* feat(keebwerk): added VIA support keymap for keebwerk nano slider

Added VIA support for keebwerk nano slider, VIA json is keebwerk_nano_via.json
Fixed midi2vol keymap where comma symbol is missing from enum "custom_layers"

* feat(keebwerk): removed VIA json as requested

* Update keyboards/keebwerk/nano_slider/keymaps/via/keymap.c

* Update keyboards/keebwerk/nano_slider/keymaps/via/keymap.c

* Fix(PR): removed file as requested

keyboards/keebwerk/nano_slider/keymaps/via/keymap.c

@@ -0,0 +1,67 @@
+/* Copyright 2020 Duckle
+ *
+ * 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/>.
+ */
+#include QMK_KEYBOARD_H
+#include "analog.h"
+#include "qmk_midi.h"
+
+enum layer_names {
+    _BASE,
+    _FN,
+    _MEDIA,
+    _FN2
+};
+
+/* Defines the keycodes used by our macros in process_record_user */
+enum custom_keycodes { /* In order to add more volume controls, add here a custom keycode, ex: VLC */
+    DEFAULT= SAFE_RANGE,SPOTIFY,DISCORD,CHROME/*,VLC*/
+};
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    /* Base */
+    [_BASE] = LAYOUT(
+        TO(_FN),
+        KC_1,    KC_2,    KC_3,
+        KC_4,    KC_5,    KC_6,    KC_0
+    ),
+    [_FN] = LAYOUT(
+        TO(_MEDIA),
+        RGB_TOG, RGB_MOD, RGB_VAI,
+        RGB_SAI, BL_BRTG, BL_STEP, KC_LSFT
+    ),
+    [_MEDIA] = LAYOUT(
+        TO(_BASE),
+        KC_VOLD, KC_VOLU, KC_F24,
+        KC_MRWD, KC_MFFD, KC_F23, KC_MPLY
+    ),
+    [_FN2] = LAYOUT(
+        _______,
+        _______, _______, _______,
+        _______, _______, _______, _______
+    )
+};
+
+uint8_t divisor = 0;
+
+void slider(void) {
+    if (divisor++) { // only run the slider function 1/256 times it's called
+        return;
+    }
+
+    midi_send_cc(&midi_device, 2, 0x3E, 0x7F - (analogReadPin(SLIDER_PIN) >> 3));
+}
+
+void matrix_scan_user(void) {
+    slider();
+}