Better config.json handling

[starikcetin]

Our way of handling config.json file is not friendly for project maintainers.

We should allow the project maintainers to execute the application on a specific folder. Then the program will search for a config.json file in that directory and act accordingly.

This will allow them to commit the config.json file to their own repositories and use the tool externally, targeting their project's config.json.

This might also be useful in the future if we decide to introduce support for multiple configs.