docs: global rand seed deprecated in go1.20

The math/rand package now automatically seeds the global random number
generator with a random value, and the top-level Seed function has been
deprecated.

Author: mroth

README.md

@@ -20,8 +20,6 @@ import (
 )
 
 func main() {
-    rand.Seed(time.Now().UTC().UnixNano()) // always seed random!
-
     chooser, _ := weightedrand.NewChooser(
         weightedrand.NewChoice('🍒', 0),
         weightedrand.NewChoice('🍋', 1),

examples/frequency/main.go

@@ -3,15 +3,11 @@ package main
 import (
 	"fmt"
 	"log"
-	"math/rand"
-	"time"
 
 	"github.com/mroth/weightedrand/v2"
 )
 
 func main() {
-	rand.Seed(time.Now().UTC().UnixNano()) // always seed random!
-
 	c, err := weightedrand.NewChooser(
 		weightedrand.NewChoice('🍒', 0),
 		weightedrand.NewChoice('🍋', 1),

weightedrand_test.go

@@ -34,7 +34,7 @@ func Example() {
 *******************************************************************************/
 
 func init() {
-	rand.Seed(time.Now().UTC().UnixNano())
+	rand.Seed(time.Now().UTC().UnixNano()) // only necessary prior to go1.20
 }
 
 const (