add documentation how to install server on ubuntu 20.04 and add server version stuff

MareSynchronosServer/MareSynchronos.API/ConnectionDto.cs

@@ -0,0 +1,10 @@
+namespace MareSynchronos.API
+{
+    public record ConnectionDto
+    {
+        public int ServerVersion { get; set; }
+        public bool IsAdmin { get; set; }
+        public bool IsModerator { get; set; }
+        public string UID { get; set; }
+    }
+}