enhancement: Improving railway configuration of karma gap backend

[FrancoAguzzi]

@RafaDSan can you add a description to this issue based on the feedbacks you received and want to implement?

[RafaDSan]

• [x] Add the output of the task in this issue comment section
• [x] Low down the resource limits of the server
• [ ] Create a documentation explaining each field of the database
• [ ] Add README

[RafaDSan]

Task output:

API endpoint on railway: https://trustful-karma-gap-backend-staging.up.railway.app/