Link the main page example to the HelloWorldHummingbird project

Co-authored-by: Joseph Heck <[email protected]>

Author: euanh

Sources/swift-container-plugin/Documentation.docc/Swift-Container-Plugin.md

@@ -27,7 +27,8 @@ To use the plugin:
 - <doc:authentication>
 ### Build and publish a container image
 
-After adding the plugin to your project, you can build and publish a container image in one step:
+After adding the plugin to your project, you can build and publish a container image in one step.
+Here is how to build the [HelloWorld example](https://github.com/apple/swift-container-plugin/tree/main/Examples/HelloWorldHummingbird) as a static binary for Linux running the `x86_64` architecture:
 
 ```
 % swift package --swift-sdk x86_64-swift-linux-musl \