Added Zephyr Project

Zephyr/src/main.c

@@ -0,0 +1,7 @@
+#include <zephyr/kernel.h>
+#include <zephyr/sys/printk.h>
+
+int main(void) {
+  printk("Hello from my freestanding Zephyr app!\n");
+  return 0;
+}