Routers are not a great example to build upon

[jugonzal]

Students who use the skeleton are facing two basic problems while following this template:

1. Because the router modules have only ONE route each, it is not obvious how to create a module that has multiple routes within. This would be easily fixable just by adding a second route to users.js for example.

2. For some reason, since Knex was removed, we also lost the data abstraction layer. While there may not be a lot of need for it, putting everything in the router sets them for other challenges when doing this project as a team. Once team member may be working on routes and another on database queries, and with this architecture both of them would be working out of the same files, increasing the rate of conflicts.

These issues are only obvious since the skeleton was refactored for the new curriculum