address Nate's feedback

Author: Azoy

CHANGELOG.md

@@ -77,16 +77,17 @@ Swift 4.2
 * [SE-0202][]
 
   The standard library now provides a unified set of randomization functionality.
-  Integer types, floating point types, and Bool all introduce a new random
-  function.
+  Integer types, floating point types, and Bool all introduce a new static
+  method that creates a random value.
 
   ```swift
   let diceRoll = Int.random(in: 1 ... 6)
   let randomUnit = Double.random(in: 0 ..< 1)
   let randomBool = Bool.random()
   ```
 
-  There are also a couple of collection additions included as well.
+  There are also additions to select a random element from a collection or
+  shuffle its contents.
 
   ```swift
   let greetings = ["hey", "hello", "hi", "hola"]
@@ -96,27 +97,20 @@ Swift 4.2
 
   Core to the randomization functionality is a new `RandomNumberGenerator`
   protocol. The standard library defines its own random number generator
-  called `SystemRandomNumberGenerator` which is backed by a secure and thread
-  safe random number generator on each platform. All the randomization functions
-  have a `using:` parameter that take a `RandomNumberGenerator` that users can
-  pass in their own random number generator.
+  called `SystemRandomNumberGenerator` which is backed by a secure and
+  thread-safe random number generator on each platform. All the randomization
+  functions have a `using:` parameter that take a `RandomNumberGenerator` that
+  users can pass in their own random number generator.
 
   ```swift
   struct MersenneTwister: RandomNumberGenerator {
     func next() -> UInt64 {
-      // Algorithm stuff here
+      // implementation
     }
   }
 
   var mt = MersenneTwister()
   let diceRoll = Int.random(in: 1 ... 6, using: &mt)
-  let randomUnit = Double.random(in: 0 ..< 1, using: &mt)
-  let randomBool = Bool.random(using: &mt)
-  
-  // Collection additions
-  let greetings = ["hey", "hello", "hi", "hola"]
-  let randomGreeting = greetings.randomElement(using: &mt)! // This returns an Optional
-  let newGreetings = greetings.shuffled(using: &mt) // ["hola", "hi", "hey", "hello"]
   ```
 
 * [SE-0194][]