docs: add documentation for WithListener option Redpanda

Add documentation for the additional listener option (WithListener) for the
Redpanda module

Signed-off-by: Santiago Jimenez Giraldo <sago2k8@gmail.com>

docs/modules/redpanda.md

@@ -51,6 +51,26 @@ for Redpanda. E.g. `testcontainers.WithImage("docker.redpanda.com/redpandadata/r
 
 If you need to enable TLS use `WithTLS` with a valid PEM encoded certificate and key.
 
+#### Additional Listener
+
+There are scenarios where additional listeners are needed, for example if you
+want to consume/from another container in the same network
+
+You can use the `WithListener` option to add a listener to the Redpanda container.
+<!--codeinclude-->
+[Register additional listener](../../modules/redpanda/redpanda_test.go) inside_block:withListenerRP
+<!--/codeinclude-->
+
+Container defined in the same network
+<!--codeinclude-->
+[Start Kcat container](../../modules/redpanda/redpanda_test.go) inside_block:withListenerKcat
+<!--/codeinclude-->
+
+Produce messages using the new registered listener
+<!--codeinclude-->
+[Produce/consume via registered listener](../../modules/redpanda/redpanda_test.go) inside_block:withListenerExec
+<!--/codeinclude-->
+
 ### Container Methods
 
 The Redpanda container exposes the following methods:

modules/redpanda/redpanda_test.go

@@ -283,19 +283,23 @@ func TestRedpandaWithTLS(t *testing.T) {
 
 func TestRedpandaListener_Simple(t *testing.T) {
 	ctx := context.Background()
+
 	// 1. Create network
 	rpNetwork, err := network.New(ctx, network.WithCheckDuplicate())
 	require.NoError(t, err)
 
 	// 2. Start Redpanda container
+	// withListenerRP {
 	container, err := RunContainer(ctx,
 		testcontainers.WithImage("redpandadata/redpanda:v23.2.18"),
 		network.WithNetwork([]string{"redpanda-host"}, rpNetwork),
 		WithListener("redpanda:29092"), WithAutoCreateTopics(),
 	)
+	// }
 	require.NoError(t, err)
 
 	// 3. Start KCat container
+	// withListenerKcat {
 	kcat, err := testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
 		ContainerRequest: testcontainers.ContainerRequest{
 			Image: "confluentinc/cp-kcat:7.4.1",
@@ -312,15 +316,18 @@ func TestRedpandaListener_Simple(t *testing.T) {
 		},
 		Started: true,
 	})
+	// }
 
 	require.NoError(t, err)
 
 	// 4. Copy message to kcat
 	err = kcat.CopyToContainer(ctx, []byte("Message produced by kcat"), "/tmp/msgs.txt", 700)
 	require.NoError(t, err)
 
-	// 5. Produce mesaage to Redpanda
+	// 5. Produce message to Redpanda
+	// withListenerExec {
 	_, _, err = kcat.Exec(ctx, []string{"kcat", "-b", "redpanda:29092", "-t", "msgs", "-P", "-l", "/tmp/msgs.txt"})
+	// }
 
 	require.NoError(t, err)