Adding a document (missing example)

[EskelCz]

Maybe I'm missing something, but the readme is really missing a simple example on how to add a document in the correct data format. In issues here and at stack overflow, I've read multiple threads of people confused about this.

In documentation there is the GeoCollection.add method (which I assume is the best way to go about it) but the information on its data object structure is missing.
https://geofirestore.com/modules/_geofirestoretypes_.geofirestoretypes.html#documentdata

I have to dig way down into typescript definition to figure out it's just a wrapper for a GeoPoint: https://github.com/geofirestore/geofirestore-js/blob/aa80c71/src/GeoFirestoreTypes.ts#L13

So for something so basic to the function of this library, this feels inadequate.
Thanks for your consideration.

[MichaelSolati]

Noted, and thank you for the feedback. I'd say, if you wanted to open a PR and add it to the readme that would be awesome! (If not I'll try to get to it this week, I've been traveling a lot and just moved so it's been difficult)