Change prompt to be more distinguishable from async messages

Author: nshafer

examples/cli/cli.go

@@ -44,7 +44,7 @@ func main() {
 
 	reader := bufio.NewReader(os.Stdin)
 	for {
-		fmt.Print("> ")
+		fmt.Print("phx % ")
 
 		input, err := reader.ReadString('\n')
 		if err == io.EOF {