Create README.md for GitHub Copilot SDK for Java (#967)

* Create README.md for GitHub Copilot SDK for Java

Added README.md for GitHub Copilot SDK for Java with usage instructions and resources.

* Update java/README.md

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Clarify SDK status and repository information in README

Updated README to clarify SDK status and repository location.

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: brunoborges

java/README.md

@@ -0,0 +1,82 @@
+# GitHub Copilot SDK for Java
+
+Java SDK for programmatic control of GitHub Copilot CLI via JSON-RPC.
+
+> **📦 The Java SDK is maintained in a separate repository: [`github/copilot-sdk-java`](https://github.com/github/copilot-sdk-java)**
+>
+> **Note:** This SDK is in technical preview and may change in breaking ways.
+
+[![Build](https://github.com/github/copilot-sdk-java/actions/workflows/build-test.yml/badge.svg)](https://github.com/github/copilot-sdk-java/actions/workflows/build-test.yml)
+[![Maven Central](https://img.shields.io/maven-central/v/com.github/copilot-sdk-java)](https://central.sonatype.com/artifact/com.github/copilot-sdk-java)
+[![Java 17+](https://img.shields.io/badge/Java-17%2B-blue?logo=openjdk&logoColor=white)](https://openjdk.org/)
+[![Documentation](https://img.shields.io/badge/docs-online-brightgreen)](https://github.github.io/copilot-sdk-java/)
+[![Javadoc](https://javadoc.io/badge2/com.github/copilot-sdk-java/javadoc.svg)](https://javadoc.io/doc/com.github/copilot-sdk-java/latest/index.html)
+
+## Quick Start
+
+```java
+import com.github.copilot.sdk.CopilotClient;
+import com.github.copilot.sdk.events.AssistantMessageEvent;
+import com.github.copilot.sdk.events.SessionIdleEvent;
+import com.github.copilot.sdk.json.MessageOptions;
+import com.github.copilot.sdk.json.PermissionHandler;
+import com.github.copilot.sdk.json.SessionConfig;
+
+public class QuickStart {
+    public static void main(String[] args) throws Exception {
+        // Create and start client
+        try (var client = new CopilotClient()) {
+            client.start().get();
+
+            // Create a session (onPermissionRequest is required)
+            var session = client.createSession(
+                new SessionConfig()
+                    .setModel("gpt-5")
+                    .setOnPermissionRequest(PermissionHandler.APPROVE_ALL)
+            ).get();
+
+            var done = new java.util.concurrent.CompletableFuture<Void>();
+
+            // Handle events
+            session.on(AssistantMessageEvent.class, msg ->
+                System.out.println(msg.getData().content()));
+            session.on(SessionIdleEvent.class, idle ->
+                done.complete(null));
+
+            // Send a message and wait for completion
+            session.send(new MessageOptions().setPrompt("What is 2+2?"));
+            done.get();
+        }
+    }
+}
+```
+
+## Try it with JBang
+
+Run the SDK without setting up a full project using [JBang](https://www.jbang.dev/):
+
+```bash
+jbang https://github.com/github/copilot-sdk-java/blob/main/jbang-example.java
+```
+
+## Documentation & Resources
+
+| Resource | Link |
+|----------|------|
+| **Full Documentation** | [github.github.io/copilot-sdk-java](https://github.github.io/copilot-sdk-java/) |
+| **Getting Started Guide** | [Documentation](https://github.github.io/copilot-sdk-java/latest/documentation.html) |
+| **API Reference (Javadoc)** | [javadoc.io](https://javadoc.io/doc/com.github/copilot-sdk-java/latest/index.html) |
+| **MCP Servers Integration** | [MCP Guide](https://github.github.io/copilot-sdk-java/latest/mcp.html) |
+| **Cookbook** | [Recipes](https://github.com/github/copilot-sdk-java/tree/main/src/site/markdown/cookbook) |
+| **Source Code** | [github/copilot-sdk-java](https://github.com/github/copilot-sdk-java) |
+| **Issues & Feature Requests** | [GitHub Issues](https://github.com/github/copilot-sdk-java/issues) |
+| **Releases** | [GitHub Releases](https://github.com/github/copilot-sdk-java/releases) |
+| **Copilot Instructions** | [copilot-sdk-java.instructions.md](https://github.com/github/copilot-sdk-java/blob/main/instructions/copilot-sdk-java.instructions.md) |
+
+## Contributing
+
+Contributions are welcome! Please see the [Contributing Guide](https://github.com/github/copilot-sdk-java/blob/main/CONTRIBUTING.md) in the GitHub Copilot SDK for Java repository.
+
+## License
+
+MIT — see [LICENSE](https://github.com/github/copilot-sdk-java/blob/main/LICENSE) for details.