add JUnit5 example and documentation

Author: kapishmalik

README.md

@@ -165,6 +165,32 @@ public class WireMockContainerExtensionTest {
 }
 ```
 
+```java
+@Testcontainers
+public class WireMockContainerExtensionJUnit5Test {
+    
+    @Container
+    public WireMockContainer wiremockServer = new WireMockContainer("2.35.0")
+            .withMapping("json-body-transformer", WireMockContainerExtensionTest.class, "json-body-transformer.json")
+            .withExtension("JSON Body Transformer", Collections.singleton("com.ninecookies.wiremock.extensions.JsonBodyTransformer"),
+                    Collections.singleton(Paths.get("target", "test-wiremock-extension", "9cookies-wiremock-extensions.jar").toFile()));
+
+    @Test
+    public void testJSONBodyTransformer() throws Exception {
+        final HttpClient client = HttpClient.newBuilder().build();
+        final HttpRequest request = HttpRequest.newBuilder()
+                .uri(wiremockServer.getRequestURI("json-body-transformer"))
+                .timeout(Duration.ofSeconds(10))
+                .header("Content-Type", "application/json")
+                .POST(HttpRequest.BodyPublishers.ofString("{\"name\":\"John Doe\"}")).build();
+
+        HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+        assertThat(response.body()).as("Wrong response body")
+                .contains("Hello, John Doe!");
+    }
+}
+```
 ## Contributing
 
 All contributions are welcome!

src/test/java/org/wiremock/integrations/testcontainers/WireMockContainerJUnit5Test.java

@@ -0,0 +1,59 @@
+package org.wiremock.integrations.testcontainers;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+@Testcontainers
+public class WireMockContainerJUnit5Test {
+
+  @Container
+  public WireMockContainer wiremockServer = new WireMockContainer("2.35.0")
+      .withMapping("hello", WireMockContainerTest.class, "hello-world.json")
+      .withMapping("hello-resource", WireMockContainerTest.class, "hello-world-resource.json")
+      .withFileFromResource("hello-world-resource-response.xml", WireMockContainerTest.class,
+          "hello-world-resource-response.xml");
+
+  @Test
+  public void helloWorld() throws Exception {
+    final HttpClient client = HttpClient.newBuilder().build();
+    final HttpRequest request = HttpRequest.newBuilder()
+        .uri(wiremockServer.getRequestURI("hello"))
+        .timeout(Duration.ofSeconds(10))
+        .header("Content-Type", "application/json")
+        .GET().build();
+
+    HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+    assertThat(response.body())
+        .as("Wrong response body")
+        .contains("Hello, world!");
+  }
+
+  @Test
+  public void helloWorldFromFile() throws Exception {
+    final HttpClient client = HttpClient.newBuilder()
+        .version(HttpClient.Version.HTTP_1_1)
+        .build();
+
+    HttpRequest request = HttpRequest.newBuilder()
+        .uri(wiremockServer.getRequestURI("hello-from-file"))
+        .timeout(Duration.ofSeconds(10))
+        .header("Content-Type", "application/json")
+        .GET()
+        .build();
+
+    HttpResponse<String> response =
+        client.send(request, HttpResponse.BodyHandlers.ofString());
+
+    assertThat(response.body())
+        .as("Wrong response body")
+        .contains("Hello, world!");
+  }
+}