Copy git action from COAsT-site to run notebooks on COAsT side

[jpolton]

Testing example_scripts has been removing from unit_test.py. All the components are tested anyway.
There is a gitAction on COAsT-site that does run the notebooks. This should be copied to COAsT to catch any errors on the code dev side, just incase.

[thogar-computer]

see https://github.com/British-Oceanographic-Data-Centre/COAsT/tree/feature/552_notebooks

@jpolton is that what you were thinking of?