Fixed huffman lut summary

src/ImageSharp/Formats/Jpeg/Components/Encoder/HuffmanLut.cs

@@ -4,12 +4,26 @@
 namespace SixLabors.ImageSharp.Formats.Jpeg.Components.Encoder
 {
     /// <summary>
-    /// TODO: THIS IS NO LONGER TRUE, INTERNAL REPRESENTATION WAS CHANGED AND THIS DOC SHOULD BE CHANGED TOO!!!
     /// A compiled look-up table representation of a huffmanSpec.
-    /// Each value maps to a int32 of which the 24 most significant bits hold the
-    /// codeword in bits and the 8 least significant bits hold the codeword size.
     /// The maximum codeword size is 16 bits.
     /// </summary>
+    /// <remarks>
+    /// <para>
+    /// Each value maps to a int32 of which the 24 most significant bits hold the
+    /// codeword in bits and the 8 least significant bits hold the codeword size.
+    /// </para>
+    /// <para>
+    /// Code value occupies 24 most significant bits as integer value.
+    /// This value is shifted to the MSB position for performance reasons.
+    /// For example, decimal value 10 is stored like this:
+    /// <code>
+    /// MSB                                LSB
+    /// 1010 0000 00000000 00000000 | 00000100
+    /// </code>
+    /// This was done to eliminate extra binary shifts in the encoder.
+    /// While code length is represented as 8 bit integer value
+    /// </para>
+    /// </remarks>
     internal readonly struct HuffmanLut
     {
         /// <summary>