[TASK] Research options to add testing to this project if and where possible

## Task Context

This task is to research any potential options to add any form of automated testing to this project whether they be unit, functional, or end to end tests.

## Acceptance Criteria

The acceptance criteria for this task is to properly explore and document any options for adding testing to this project. Any findings should include details on how to implement the test libraries/functionalities specifically for this project.

Adding a basic test to this project to show that it will work properly would definitely be a nice to have but not a requirement to complete and close out this task.

## Additional Context

Some work has been done on this in the past. However, the project has changed in various ways since then such as with the inclusion of CMake.

Please read through the [Contributing to the Project](https://github.com/jmakhack/myanimelist-cli/blob/master/CONTRIBUTING.md) document before working on this project.