Discussion on the design document

[EiffL]

I have added a design document here to document our choices of interface and implementation. This issue can be used for discussions on the docucment.

[EiffL]

Here are some examples of use cases we want to add to the design document to help constrain the interface:

• @jan-matthis : Use case of density estimation
• @EiffL : Use case with offline simulator
• @tomcharnock : Use case with a compression step

[jan-matthis]

Wrote up a proposal for a design using Pyro in design.md on my branch with external simulators, offline experiments, score compression, and density estimation.

[EiffL]

Thanks @jan-matthis, I went ahead and merged your PR, I'm keeping this issue open, and renaming it slightly to document further discussions on the design document