Add json files to create the examples in the book

[nadavrap]

I suggest to add json files (or link to json files) to help with the ATLAS examples (cohorts, characterization, pathways, incidence and more).
In the current status, if I want to reproduce the pathway analysis examples of first line treatment for hypertension that is given in the book (Chapter 11.9), I need to define many concept sets and cohorts. Or I need to look for one that was created in the ATLAS-demo and make sure that it corresponds the description which is not a trivial task.

I would like to contribute, but I'm not sure what would be the best option. I thought of severals:

1. Link to (or give the id of) the example in ATLAS-demo. The limitation - If someone change the example on the web if it is not locked.
2. Create a json file and add as plain text to the book of OHDSI
3. Create a json file and put a link in the Book. Q: Where to store the link? Under books's files (e.g. extras folder) or external location (personal repo?).
4. Create a script that load a json file to the ATLAS using WebAPI. Limitation - I'm not sure if it's fully implemented for characterization, PLP etc., or it is only support cohort and concept sets upload.

Any suggestions?