Auto merge of rust-lang#21609 - GarrettHeel:master, r=steveklabnik

Now that it's no longer feature gated, add docs for wildcard syntax.

Author: bors

src/doc/trpl/crates-and-modules.md

@@ -551,6 +551,10 @@ module, we now have a `phrases::japanese::hello()` function and a
 `phrases::japanese::farewells::goodbye()`. Our internal organization doesn't
 define our external interface.
 
+Here we have a `pub use` for each function we want to bring into the 
+`japanese` scope. We could alternatively use the wildcard syntax to include
+everything from `greetings` into the current scope: `pub use self::greetings::*`. 
+
 Also, note that we `pub use`d before we declared our `mod`s. Rust requires that
 `use` declarations go first.