Harmonise code samples across languages

[KirstieJane]

[caveat] This might be a bit of a big task (I think @Park-Patrick can do it for matlab and python, but we might want to recruit a new contributor to translate into R or any other language).

Before we get started it would be great to be all on the same page about what we're trying to achieve: (see #57 - what is the point of the code samples in this repo).

Once #57 is closed out, the next step is to make sure that what's inside the folders (matlabCode, pythonCode etc) are the same.

I think this means making sure that:

• Each folder has a README file that contains basically the same information, explaining how you can use the scripts and why you'd want to
• The files are all the same. At the moment the pythonCode folder only has createBIDS_dataset_description_json.py while the matlabCode has a lot of different files. It would be great if these were harmonised.

Once these steps are complete, we could get back to #35 and add in an RCode folder ✨