add notes for approach to GIS data modeling

[capsulecorplab]

closes #2

[TristanDamron]

Can we flesh these notes out? I'd like to have more thorough documentation that will help guide this project.

[TristanDamron]

@capsulecorplab just following up on my request to flesh this doc out--I know you've got a lot going on, but I wanted to make sure this PR was being accounted for.

[capsulecorplab]

@TristanDamron These were the notes we collected during our GIS data modeling discussion. What other content did you have in mind that we might want to capture here?

[TristanDamron]

I was under the impression that the notes we put together in our meeting would be fleshed out into a formal design doc that we would use to guide the project. If we want to take a doc-driven-development approach here, I think we need to thoroughly document these ideas.

[capsulecorplab]

I'll set this PR to draft then, since it sounds like issue #2 needs to be refined to serve more as a kind of schema for drafting a design doc that can guide an implementation.