title: Cowboy: How do you present a static html file from a handler?
body: <p>I am using cowboy and I have a post method to a handler which checks for user name and password. This all works great.</p>
  
  <p>Many of the examples show how to return a simple hello message in response. Unfortunately, I would like to serve up a html file in response to the correct details but I cannot see how to do this from a handler?</p>
  
  <p>I know how to serve static files using the cowboy static file handler but I do not know how to serve a static file from my own handler.</p>