Documentation issue: Rules Tutorial

Documentation URL: https://docs.bazel.build/versions/main/skylark/rules-tutorial.html

The above page says: "In the implementation function, the target will be accessible as a [Target](https://docs.bazel.build/versions/main/skylark/lib/Target.html) object. For example, view the files returned by the target using [Target.files](https://docs.bazel.build/versions/main/skylark/lib/Target.html#modules.Target.files)."

This needs a clarification / supporting example. Target.files isn't defined in the implementation function.