updated README with build instructions. used README from flex-sdk repository as template
updated README with build instructions. used README from flex-sdk repository as template

SlavaRa/flex-flexunit,apache/flex-flexunit,SlavaRa/flex-flexunit,apache/flex-flexunit,apache/flex-flexunit,apache/flex-flexunit,SlavaRa/flex-flexunit,SlavaRa/flex-flexunit