🧑‍💻 🐛 Country Catalogue Assignment --- Remove mention of area in add docstring

[jameshughes89]

What

Remove the mention of the area parameter in the add method in the CountryCatalogue class.

Why

It's not actually a parameter for the method.

Testing

YOLO

Additional Notes

1. I believe this is from a previous version of the assignment where the add method created the Country object and then appended.
2. Oddly, this issue did not exist in the assignments repo.

[jameshughes89]

I changed out the ipynb file by downloading from colab to eliminate any issues with the pycharm editing of the ipynb file.

Also, looks like the ipynb file keeps track of how many times a cell was run, which is neat. Those fields in the file are changed here but should not have any functional implication.