feat: use relative path instead of `cwd` for `credentials.ini` file

[afonsojramos]

📑 Description

Closes #47

@sitiom tested locally and everything seemed to work. Let me know if it is good to merge for you as well.

✅ Checks

• [x] code: My pull request adheres to the code style of this project
• [x] docs: Added / updated
• [ ] tests: All the tests have passed