Move Zephyr app into subdirectory.

app/src/main.c

@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2020 Peter Johanson
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <zephyr.h>
+#include <device.h>
+#include <devicetree.h>
+#include <settings/settings.h>
+
+#include <logging/log.h>
+LOG_MODULE_REGISTER(zmk, CONFIG_ZMK_LOG_LEVEL);
+
+#include <zmk/matrix.h>
+#include <zmk/kscan.h>
+#include <zmk/endpoints.h>
+
+#define ZMK_KSCAN_DEV DT_LABEL(ZMK_MATRIX_NODE_ID)
+
+void main(void)
+{
+	printk("Welcome to ZMK!\n");
+
+	if (zmk_kscan_init(ZMK_KSCAN_DEV) != 0)
+	{
+		return;
+	}
+
+	if (zmk_endpoints_init())
+	{
+		printk("ENDPOINT INIT FAILED\n");
+		return;
+	}
+
+#ifdef CONFIG_SETTINGS
+	settings_load();
+#endif
+}