module Asciidoctor

def self.render_file(filename, options = {}, &block)

otherwise the rendered output String is returned
returns nothing if the rendered output String is written to a file,

block - a callback block for handling include::[] directives
see Asciidoctor::Document#initialize for details
options - a Hash of options to control processing (default: {})
input - the String AsciiDoc source filename

and render it to the specified backend format
Public: Parse the contents of the AsciiDoc source file into an Asciidoctor::Document 
def self.render_file(filename, options = {}, &block)
  Asciidoctor.render(File.new(filename), options, &block)
end