Update TextFieldParser.xml (dotnet#4855)

Add the word `using` to make the following sentence correct:

> ...while [USING] the `ReadFields` method to extract fields of text is similar to splitting the strings.

Author: ericmutta

xml/Microsoft.VisualBasic.FileIO/TextFieldParser.xml

@@ -31,7 +31,7 @@
       <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- The `TextFieldParser` object provides methods and properties for parsing structured text files. Parsing a text file with the `TextFieldParser` is similar to iterating over a text file, while the `ReadFields` method to extract fields of text is similar to splitting the strings.  
+ The `TextFieldParser` object provides methods and properties for parsing structured text files. Parsing a text file with the `TextFieldParser` is similar to iterating over a text file, while using the `ReadFields` method to extract fields of text is similar to splitting the strings.  
   
  The `TextFieldParser` can parse two types of files: delimited or fixed-width. Some properties, such as `Delimiters` and `HasFieldsEnclosedInQuotes` are meaningful only when working with delimited files, while the `FieldWidths` property is meaningful only when working with fixed-width files.