Added preserve-package to the repo README.md.

Author: shaunsmith

README.md

@@ -28,6 +28,7 @@ Demos for building native images, including configurations and setup steps for v
 * [list-files](native-image/list-files/) - Shows how to create a native executable from the command line, and then apply Profile-Guided Optimization (PGO)
 * [native-build-tools](native-image/native-build-tools/) - Contains two Java projects, and shows how to create native executables from those applications using [Maven](https://graalvm.github.io/native-build-tools/latest/maven-plugin.html) and [Gradle](https://graalvm.github.io/native-build-tools/latest/gradle-plugin.html) plugins for GraalVM Native Image
 * [wasm-javac](native-image/wasm-javac/) - Illustrates how to use the new experimental WebAssembly backend in GraalVM to compile `javac` into a Wasm module, which can then run either on the command line or in the browser. [Check out the live demo here](https://graalvm.github.io/graalvm-demos/native-image/wasm-javac/).
+* [preserve-package](native-image/preserve-package/) - Demonstrates how to use the -H:Preserve option to include all classes in a package in a native image instead of using JSON metadata configuration.
 
 ### Configure
 Demos illustrating how to compile applications with Native Image that use some dynamic Java features including reflection, resource access, and so on.