sort: add example for Strings

Change-Id: I33f0e2362e85287b493d9279d43b760733e2abcb
Reviewed-on: https://go-review.googlesource.com/48831
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan Mills <bcmills@google.com>

src/sort/example_test.go

@@ -69,3 +69,10 @@ func ExampleSliceStable() {
 	// Output: By name: [{Alice 25} {Alice 75} {Alice 75} {Bob 75} {Bob 25} {Colin 25} {Elizabeth 75} {Elizabeth 25}]
 	// By age,name: [{Alice 25} {Bob 25} {Colin 25} {Elizabeth 25} {Alice 75} {Alice 75} {Bob 75} {Elizabeth 75}]
 }
+
+func ExampleStrings() {
+	s := []string{"Go", "Bravo", "Gopher", "Alpha", "Grin", "Delta"}
+	sort.Strings(s)
+	fmt.Println(s)
+	// Output: [Alpha Bravo Delta Go Gopher Grin]
+}