Switch root namespace to "RobloxFiles"

In case there are any future libraries written for Roblox in C#, I want to avoid running into any namespace collisions. Its best to keep everything pertaining to this project nested in its own unique namespace.

XmlFormat/PropertyTokens/PhysicalProperties.cs

@@ -1,8 +1,8 @@
 using System;
 using System.Xml;
-using Roblox.DataTypes;
+using RobloxFiles.DataTypes;
 
-namespace Roblox.XmlFormat.PropertyTokens
+namespace RobloxFiles.XmlFormat.PropertyTokens
 {
     public class PhysicalPropertiesToken : IXmlPropertyToken
     {