add an openapi spec to design/document the api

[sonalranjit]

It would be great to have an open api doc to collaboratively design and document on an open api specification document which can be implemented when the server is ready.

[Arpanio]

I haven't worked on this before. Miranda seems to be quite a few commits ahead in her local repo. Maybe we should pull her in here.

[sonalranjit]

Yes she should commit her code into this repo.
We can design the api with an open-api spec before we ever start coding. The spec can be written in yaml file so it can be committed here.

https://swagger.io/docs/specification/basic-structure/
^^ if this is of interest to you, you can look into this. we can translate jim's api doc in the wiki into an open api spec.