function help() {
	var names;
	var o;
	var i;

	if ( HELP_TEXT ) {
		return HELP_TEXT;
	}
	names = objectKeys( TUTORIALS );
	HELP_TEXT = '\n';
	for ( i = 0; i < names.length; i++ ) {
		o = TUTORIALS[ names[ i ] ];
		HELP_TEXT += names[ i ] + '\n';
		HELP_TEXT += '    ';
		if ( o.desc ) {
			HELP_TEXT += TUTORIALS[ names[ i ] ].desc;
		} else {
			HELP_TEXT += '(no description available)';
		}
		HELP_TEXT += '\n\n';
	}
	return HELP_TEXT;
}
Returns tutorial help text.

@private
@returns {string} tutorial help text