Introduce submit-stac.ipynb jupyter file

[IanMayo]

Create a new jupyter file, include steps to create a collection, an item, and some assets (a combination of plain text files and random images).

The json files, text files and images should be present in a mock-data subfolder of the repo.

Initially this can include any-old-data that meets the stac requirements

[Vierod]

Support for this has recently been added to pystac-client which might allow for 2 way communication without alot of additional code.

See discussion:
stac-utils/pystac-client#241
stac-utils/pystac-client#698

But incomplete currently.

[Vierod]

Note here we should probably be focused on OGC-API Features (Postgres, SQLite) not STAC as it's being set up here (indexed local directory on the server)

[Vierod]

https://owslib.readthedocs.io/en/latest/usage.html#ogc-api-features-part-4-create-replace-update-and-delete