Process the documentation with Markdown to produce HTML.

def markdown(self,md,base_url='..'):
        """
        Process the documentation with Markdown to produce HTML.
        """
        print("\nProcessing documentation comments...")
        ford.sourceform.set_base_url(base_url)        
        if self.settings['warn'].lower() == 'true': print()
        for src in self.allfiles:
            src.markdown(md, self)