add FAQ section for why the HDMF schema language was created

[bendichter]

No description provided.

[bendichter]

@oruebel I took some liberties here and I want to make sure this represents the position of the group before adding it to the documentation. Let me know your thoughts. Happy to discuss.

[oruebel]

I haven't had the chance to review the text in detail, but in general it looks ok. Retracing history after the fact is always challenging and some of that history comes also from NWB 1. Just a couple of high-level comments:

1. The initial goal of NWB 2 was to take NWB 1 and make it usable. NWB 1 introduced the notion of the schema but it didn't use a formal language. If you look here, the schema for NWB 1 was a large, hand-written Python dict with no formal API or formally defined structure. And so part of the initial development of NWB 2 was to formalize the schema and make it usable.
2. Another piece of the puzzle (you are speaking in part to that in your text) is that we needed a schema language to describe array-based data formats. In particular it needed to support the primitives of HDF5 since those were the ones that NWB 1 used. Unfortunately, there are no standard schema formats for array formats (e.g., HDF5).
3. However, the goal was to make the language easy to use, and so using JSON/YAML as standard format for the schema so that it can be used across platforms and integrated with existing tool-chains, e.g, json-schema was part of that strategy.

[bendichter]

@oruebel ok, I added a bit from your comments. (this isn't high priority, we can put it on the back burner while you get the proposals out)

[oruebel]

Sounds good