docs: improvements to source code documentation (#1236)

src/network.h

@@ -1,7 +1,4 @@
-// Created by loki on 12/27/19.
-
-#ifndef SUNSHINE_NETWORK_H
-#define SUNSHINE_NETWORK_H
+#pragma once
 
 #include <tuple>
 
@@ -34,5 +31,3 @@ namespace net {
   host_t
   host_create(ENetAddress &addr, std::size_t peers, std::uint16_t port);
 }  // namespace net
-
-#endif  // SUNSHINE_NETWORK_H