SelectMany method `s description  added
SelectMany method `s description  added

sickboy/LINQ4ES2015,Fermium-co/LINQ4ES2015,Fermium-co/LINQ4ES2015,sickboy/LINQ4ES2015,ghorbani77/LINQ4ES2015,sickboy/LINQ4ES2015,ghorbani77/LINQ4ES2015