Add line endings normalization

Since template files (Assets/Terasurware/Editor/EntityTemplate*.txt) have `\n` (0x0a) as line ending, output of ExcelImporterMaker contains different line endings (`0x0a` for template part, `0x0d,0x0a` for generated part(`StringBuilder.AppendLine()`)) in Windows environment.
This changeset fixes it by normalizing and replacing line endings properly.

Assets/Terasurware/Editor/ExcelImporterMaker.cs

@@ -219,6 +219,7 @@ void ExportEntity()
     {
         string templateFilePath = (sepalateSheet) ? "Assets/Terasurware/Editor/EntityTemplate2.txt" : "Assets/Terasurware/Editor/EntityTemplate.txt";
         string entittyTemplate = File.ReadAllText(templateFilePath);
+        entittyTemplate = entittyTemplate.Replace("\r\n", "\n").Replace("\n", System.Environment.NewLine);
         StringBuilder builder = new StringBuilder();
         bool isInbetweenArray = false;
         foreach (ExcelRowParameter row in typeList)