Support additional newline formats

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

@@ -7,9 +7,26 @@ namespace UniversalEditor.IO
 {
     public enum NewLineSequence
     {
+        /// <summary>
+        /// Determines the new line sequence based on the system default (CR on Mac OS up to version 9, LF on Linux,
+        /// CRLF on Windows).
+        /// </summary>
         Default = -1,
+        /// <summary>
+        /// Uses the carriage return ('\r', ^M, 0x0D) as the new line sequence.
+        /// </summary>
         CarriageReturn = 1,
+        /// <summary>
+        /// Uses the line feed ('\n', ^J, 0x0A) as the new line sequence.
+        /// </summary>
         LineFeed = 2,
-        CarriageReturnLineFeed = 3
+        /// <summary>
+        /// Uses a combination of carriage return and line feed ("\r\n", ^M^J, {0x0D, 0x0A}) as the new line sequence.
+        /// </summary>
+        CarriageReturnLineFeed = 3,
+        /// <summary>
+        /// Uses a combination of line feed and carriage return ("\n\r", ^J^M, {0x0A, 0x0D}) as the new line sequence.
+        /// </summary>
+        LineFeedCarriageReturn = 4
     }
 }