Frame closures less in terms of Obj-C and C blocks (#213)

Fixes: rdar://118579466

Author: amartini51

TSPL.docc/LanguageGuide/Closures.md

@@ -4,8 +4,9 @@ Group code that executes together, without creating a named function.
 
 *Closures* are self-contained blocks of functionality
 that can be passed around and used in your code.
-Closures in Swift are similar to blocks in C and Objective-C
-and to lambdas in other programming languages.
+Closures in Swift are similar
+to closures, anonymous functions, lambdas, and blocks
+in other programming languages.
 
 Closures can capture and store references to any constants and variables
 from the context in which they're defined.