Clean architecture project could be better structured on packages, to show clearly the layers

[bpstelios10]

Article and Module Links
Clean Architecture with Spring Boot

Describe the Issue
The article does a very good job to present classes by layers. This could be done on the project at package level too. This is for 3 reasons:

• Some of the classes are not mentioned in the article, so people can reference the project as documentation.
• It is not a good java practice to put all in one package
• MOST IMPORTANT imo is that people can clearly see that entities package doesnt depend on anything, usecases package only has dependencies to entities package etc. This makes even more clear the rule 'a higher level must never depend on a lower one'

Expected Behavior
Similar

[bpstelios10]

I have the solution ready too, if i could get granted access (for creating feature branch and PR).