How to create your input type in modx Revo 2.0?

like here, or meaning something else?

System -> content types -> new content type.
MIME-type Google very easy for your type (such as xls mime or content type xls)
But one subtlety, if you specify the binary — why the file is not downloaded when I created a document of its type. It is necessary to remove a Daw binari. When you create a document, put in the settings tab — Content Disposition: attachment and choose your created type. Then will be downloaded.