Update README with JAR distribution instructions

Author: gradwahl

README.md

@@ -16,12 +16,30 @@ Or with PowerShell:
 
 Requires JDK 17+.
 
+The built JAR is written to:
+
+```text
+target/java-254-client.jar
+```
+
+The build adds the JARs from `lib/` to the application manifest, allowing
+`target/java-254-client.jar` to be launched directly.
+
 ## Run
 
 ```bat
 run.bat
 ```
 
+Using `run.bat` is recommended because it supplies the Java options used by
+LWJGL and starts the client with the default server settings.
+
+You can also launch the packaged JAR directly:
+
+```powershell
+java -jar target/java-254-client.jar
+```
+
 Args: `nodeId portOffset [lowmem|highmem] [free|members] storeid`
 
 The port-offset controls both HTTP and game ports:
@@ -35,3 +53,20 @@ The port-offset controls both HTTP and game ports:
 | `run-8888.bat` | 8888 | 52402 | 8808 |
 
 If your server uses a non-standard split (e.g. HTTP 8080 but game 43594), edit `getCodeBase()` in `src/main/java/jagex2/client/Client.java`.
+
+## Distribution
+
+The JAR contains the compiled client classes, so the `target/classes/` folder
+is not needed. The dependency JARs are separate and must be distributed with
+the client:
+
+```text
+Java-254-Client/
+|-- lib/
+|   `-- *.jar
+`-- target/
+    `-- java-254-client.jar
+```
+
+Keep the `lib/` and `target/` folders in these relative locations. Moving the
+JAR out of `target/` will prevent it from finding the libraries in `lib/`.