docs: add examples from intro (#304)

examples/src/main/java/org/example/WebKitScreenshot.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) Microsoft Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.example;
+
+import com.microsoft.playwright.*;
+import java.nio.file.Paths;
+
+public class WebKitScreenshot {
+  public static void main(String[] args) {
+    try (Playwright playwright = Playwright.create()) {
+      Browser browser = playwright.webkit().launch();
+      Page page = browser.newPage();
+      page.navigate("http://whatsmyuseragent.org/");
+      page.screenshot(new Page.ScreenshotOptions().withPath(Paths.get("example.png")));
+    }
+  }
+}