function onRead( error, file ) {
		if ( error ) {
			debug( 'Encountered an error when attempting to read file: %s', error.message );
			return done();
		}
		debug( 'Successfully read file.' );

		debug( 'Converting file content to HTML...' );
		toHTML( file, onHTML );
	}
Callback invoked upon reading a file.

@private
@param {(Error|null)} error - error object
@param {Buffer} file - file
@returns {void}