Update 10-Closures.md

Author: HariAcidReign

Notes/10-Closures.md

@@ -23,3 +23,5 @@ When functions are returned from another fun, they still maintain their lexical
 - When y is returned, not only is the fun returned but the entire closure (fun y + its lexical scope) is returned and put inside z. So when z is used 
 somewhere else in program, it still remembers var a inside x()
 
+### Uses of Closure
+Module Design Pattern, Currying, Functions like once(fun that can be run only once), memoize, maintaining state in async world, setTimeout, iterators...