Fix typo in TextAlignLast.cs

Change "etting" to "setting".

Author: ericmutta

src/AngleSharp.Css/Dom/TextAlignLast.cs

@@ -8,7 +8,7 @@ public enum TextAlignLast : byte
 		/// <summary>
 		/// The affected line is aligned per the value of text-align, unless
 		/// text-align is justify, in which case the effect is the same as 
-		/// etting text-align-last to left.
+		/// setting text-align-last to left.
 		/// </summary>
 		Auto,
 		/// <summary>