load_json function missing in models.py

[mhagdorn]

Section 33-code-decoupling-abstraction, exercise Add an Additional DataSource refers to function load_json in models. However, this function does not exist in any of the branches of python-intermediate-inflammation

[bielsnohr]

This is the state of Thomas' original course content for section 3: https://github.com/ukaea-rse-training/python-intermediate-development

And this is the project repo that we use, which might differ slightly: https://github.com/ukaea-rse-training/python-intermediate-inflammation