an actual database

[yoel123]

as of now, we don't have an actual standard database, while I use it as a relational database.

if I want to use this project to teach people it shod use an actual database or a couple (a couple of databases will teach more stuff but can turn into a nightmare scenario).

if I had to chose I would use SQLite, its only one jar and enables the use of SQL.

but that's not for now. maybe I won't add this complexity at all. for the sake of keeping everything simple.