title: how to use default ITextTemplatingEngineHost to run the processTemplate?
body: <p>I have read the docs of the T4 template which tells me I can custom a ProcessTemplate by implementation the ITextTemplatingEngineHost.</p>
  
  <p>but if I only want to custom the path of the file for .tt file and output file Is there any default ITextTemplatingEngineHost that I can use to use the ProcessTemplate function to get the output?</p>