feat: created placeholder main

Server/src/main/java/uulm/teamname/marvelous/server/Server.java

@@ -0,0 +1,7 @@
+package uulm.teamname.marvelous.server;
+
+public class Server {
+    public static void main(String[] args) {
+        System.out.println("There's nothing here yet. Sucks for you!");
+    }
+}