Replace absolute dataset paths with relative paths in configs + Add folder `data` to place datasets

[SilvioGiancola]

Currently, the configs use absolute paths for datasets. Instead, let's create an empty folder named data where users can place any dataset. If local space is limited, the data folder can contain symbolic links to the actual data storage location. By using this folder, we can refer to the relative path data\name_of_the_dataset in the config file, eliminating the need for references to /home/username.