Added comments

CSharp/Libraries/UniversalEditor.Core/IO/SeekOrigin.cs

@@ -5,10 +5,23 @@ using System.Text;
 
 namespace UniversalEditor.IO
 {
+    /// <summary>
+    /// Provides various options for determining where seeking within a stream should start.
+    /// </summary>
     public enum SeekOrigin
     {
+        /// <summary>
+        /// Indicates that seeking should start from the beginning of a stream.
+        /// </summary>
         Begin = 0,
+        /// <summary>
+        /// Indicates that seeking should start from the current position within a stream.
+        /// </summary>
         Current = 1,
+        /// <summary>
+        /// Indicates that seeking should start from the end of a stream. This usually necessiates that the amount
+        /// be specified as a negative value.
+        /// </summary>
         End = 2
     }
 }