Clean up and unify exercises

exercises/11_hashmaps/hashmaps2.rs

@@ -1,5 +1,3 @@
-// hashmaps2.rs
-//
 // We're collecting different fruits to bake a delicious fruit cake. For this,
 // we have a basket, which we'll represent in the form of a hash map. The key
 // represents the name of each fruit we collect and the value represents how
@@ -10,9 +8,6 @@
 // to insert any more of these fruits!
 //
 // Make me pass the tests!
-//
-// Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a
-// hint.
 
 use std::collections::HashMap;