Add base files and configuration for RGB underglow

app/src/behaviors/behavior_rgb_underglow.c

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2020 Nick Winans <nick@winans.codes>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#define DT_DRV_COMPAT zmk_behavior_rgb_underglow
+
+#include <device.h>
+#include <drivers/behavior.h>
+#include <logging/log.h>
+
+LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+struct behavior_rgb_underglow_config { };
+struct behavior_rgb_underglow_data { };
+
+static int behavior_rgb_underglow_init(struct device *dev)
+{
+  return 0;
+}