RxLogObservable annotation for entire class.

[VictorAlbertos]

Hi Fernando. Thanks for this awesome library :)

I've just integrated it in my current project and it works perfectly. The problem is that I needed to annotation like 50 methods xD

I've annotated every public method for every one of my repositories (and most of their methods have a public visibility). So, I think it will be nice to have an annotation with target ElementType.TYPE in order to be able to annotate an entire class (or repository for that matters), and selecting the methods to be logged based on the visibility scope selected (by default only public).

Do you think this is is technically possible? And if so, would you accept a PR -previously discussing the api?

[android10]

Another interesting feedback @VictorAlbertos. Thanks and sorry for the late reply. Will keep this in mind for the next version.