Collect models into a single directory

[gaurav]

They are currently stored in three directories: aop-models, noctua-models and signor-models. Moving these into subdirectories of a single directory -- data/? models/? -- would make it easier to grep them if needed.

[balhoff]

These are all separate git repositories; it seems a bit messy to mix them.

[gaurav]

I'm proposing that we make them subdirectories of a single directory in cam-pipeline, i.e. models/aop-models, models/noctua-models and models/signor-models. That way we could recursively search through models/* if we want to look for a particular chemical or concept across all the models. The individual Git repos would still get directories to themselves, and the existing code would stay the same -- just looking into models/aop-models instead of aop-models as they at present.

[balhoff]

@gaurav ah, makes sense!