Correct flags in helloworld and helloquic examples (#245)

* correct flag for helloworld example docs

* correct flag for helloquic example docs

* refer to -listen in helloquic flag error

Author: sarcasticadmin

_examples/helloquic/README.md

@@ -6,7 +6,7 @@ entire stream content and echos it back to the client.
 
 Server:
 ```
-go run helloquic.go -port 1234
+go run helloquic.go -listen 127.0.0.1:1234
 ```
 
 Client:

_examples/helloquic/helloquic.go

@@ -40,7 +40,7 @@ func main() {
 	flag.Parse()
 
 	if (listen.Get().Port() > 0) == (len(*remoteAddr) > 0) {
-		check(fmt.Errorf("either specify -port for server or -remote for client"))
+		check(fmt.Errorf("either specify -listen for server or -remote for client"))
 	}
 
 	if listen.Get().Port() > 0 {

_examples/helloworld/README.md

@@ -5,7 +5,7 @@ which replies back.
 
 Server:
 ```
-go run helloworld.go -port 1234
+go run helloworld.go -listen 127.0.0.1:1234
 ```
 
 Client: