Added customized AppendLine() for StringBuilder

AMWD.Common/Extensions/StringExtensions.cs

@@ -203,5 +203,16 @@ namespace System
 				return false;
 			}
 		}
+
+		/// <summary>
+		/// Appends a copy of the specified string followed by the specified line terminator
+		/// to the end of the current <see cref="StringBuilder"/> object.
+		/// </summary>
+		/// <param name="sb">The <see cref="StringBuilder"/> object.</param>
+		/// <param name="value">The string to append.</param>
+		/// <param name="newLine">The line terminator.</param>
+		/// <returns></returns>
+		public static StringBuilder AppendLine(this StringBuilder sb, string value, string newLine)
+			=> sb.Append(value).Append(newLine);
 	}
 }