Update README.md

Author: lofcz

README.md

@@ -66,7 +66,7 @@ catch (Exception e) // the file size is probably over the OpenReadStream limit
 
 ## 🏵️ Contributing
 
-To contribute, check the [mapping](https://github.com/lofcz/MimeTypeCore/blob/master/MimeTypeCore/MimeTypeCore/MimeTypeMapMapping.cs) file for the hardcoded mappings, and add new entries. Please follow the code style and alphabetical ordering. Magic headers can be contributed to [this](https://github.com/lofcz/MimeTypeCore/blob/master/MimeTypeCore/MimeTypeCore/MimeTypeMapMagicBytes.cs) file. If you are touching anything beyond that, provide relevant [test cases](https://github.com/lofcz/MimeTypeCore/tree/master/MimeTypeCore/MimeTypeCore.Tests). Thank you.
+To contribute, check the [mapping](https://github.com/lofcz/MimeTypeCore/blob/master/MimeTypeCore/MimeTypeCore/MimeTypeMapMapping.cs) file for the hardcoded mappings, and add new entries. Please follow the code style and alphabetical ordering; the included utilities [Inserter](https://github.com/lofcz/MimeTypeCore/tree/master/MimeTypeCore/MimeTypeCore.Inserter) and [Formatter](https://github.com/lofcz/MimeTypeCore/tree/master/MimeTypeCore/MimeTypeCore.Formatter) will help with that. Magic headers can be contributed to [this](https://github.com/lofcz/MimeTypeCore/blob/master/MimeTypeCore/MimeTypeCore/MimeTypeMapMagicBytes.cs) file. If you are touching anything beyond that, provide relevant [test cases](https://github.com/lofcz/MimeTypeCore/tree/master/MimeTypeCore/MimeTypeCore.Tests). Thank you.
 
 
 ## License