Make correction: function -> macro

Author: jbranchaud

elixir/expose-internal-representation.md

@@ -3,7 +3,7 @@
 Elixir is a language that has strong support for metaprogramming. It
 provides easy access to an internal representation of the code in the form
 of an Abstract Syntax Tree (AST) using maps and keyword lists. The `quote`
-function is used to expose this internal representation.
+macro is used to expose this internal representation.
 
 ```elixir
 > quote do: 2 * 2