Clarify determinism of Go playground w.r.t. random numbers

Fixes #443

examples/random-numbers/random-numbers.go

@@ -32,7 +32,7 @@ func main() {
 	// produce the same sequence of numbers each time by default.
 	// To produce varying sequences, give it a seed that changes.
 	// Note that this is not safe to use for random numbers you
-	// intend to be secret, use `crypto/rand` for those.
+	// intend to be secret; use `crypto/rand` for those.
 	s1 := rand.NewSource(time.Now().UnixNano())
 	r1 := rand.New(s1)
 

examples/random-numbers/random-numbers.hash

@@ -1,2 +1,2 @@
-f0f88939692a32975d902c94066537a6ba5ab96f
-RaoKyUd9tgC
+ea6a386e4e5602247b2203fa433d4419ff5a9489
+Enb5uJEx0Bt

examples/random-numbers/random-numbers.sh

@@ -1,3 +1,8 @@
+# Depending on where you run this sample, some of the
+# generated numbers may be different. Note that on
+# the Go playground seeding with `time.Now()` still
+# produces deterministic results due to the way the
+# playground is implemented.
 $ go run random-numbers.go
 81,87
 0.6645600532184904