💡 Add "@Generated" annotation to generated code

[mbruggmann]

What problem are you trying to solve?

The classes generated by the rewrite-templating annotation processor fail some of our errorprone rules.

Describe the solution you'd like

Add a @javax.annotation.processing.Generated("org.openrewrite.java.template.processor.RefasterTemplateProcessor") annotation to classes produced by the annotation processor.
This will make it so errorprone ignores that code if the -XepDisableWarningsInGeneratedCode argument is passed.

Have you considered any alternatives or workarounds?

Open for other suggestions!

Are you interested in contributing this feature to OpenRewrite

Possibly, but I'm not familiar with the codebase.

[timtebeek]

Fixed in #97 Thanks a lot! We might want to keep an eye on if that dependency is available to Java 9+ projects, but we can tackle that if it comes to it.