Added support for saving XML files!

Support for binary files will be coming later.

Interfaces/IRobloxFile.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
@@ -12,6 +13,8 @@ namespace RobloxFiles
     public interface IRobloxFile
     {
         Instance Contents { get; }
+
         void ReadFile(byte[] buffer);
+        void WriteFile(Stream stream);
     }
 }

Interfaces/IXmlPropertyToken.cs

@@ -10,6 +10,8 @@ namespace RobloxFiles.XmlFormat
     public interface IXmlPropertyToken
     {
         string Token { get; }
-        bool ReadToken(Property prop, XmlNode token);
+
+        bool ReadProperty(Property prop, XmlNode token);
+        void WriteProperty(Property prop, XmlDocument doc, XmlNode node);
     }
 }