🏛Further improvements for the clean architecture

[Createdd]

Currently the only use case is to request arxiv data, which is actually not 100% correct, because

1. the main use case of this repository is to provide the parsed data with a REST API
2. the other use case is to retrieve data from the arxiv website.

I think this is a great issue for beginners because it needs just a little bit of restructuring and needs an understanding of the application as a whole.

[mraza007]

Hey I can help you with this issue