add default first date (#3645)

Author: mairaw

xml/System.Globalization/DateTimeFormatInfo.xml

@@ -2840,6 +2840,10 @@ Changing the value of this property affects the following properties as well: <x
         <remarks>
           <format type="text/markdown"><![CDATA[  
   
+## Remarks
+
+The default array starts on Sunday.
+
 ## Examples  
  The following example demonstrates several methods and properties that specify date and time format patterns, native calendar name, and full and abbreviated month and day names.