Add NBN Atlas as a source

[KarenJewell]

The National Biodiversity Network(NBN) has a portal listing 1000+ datasets on biodiversity and wildlife species in the UK https://registry.nbnatlas.org/datasets

Link to the data source
https://api.nbnatlas.org

Data source type (if known)
Looks like a custom API

Organization(s) the data belongs to
NBN Atlas is a multi-owner portal

What licences are applied to the data being published? (if known)
https://docs.nbnatlas.org/guidance-for-using-data/
CC0, CC-BY, CC-BY-NC, and OGL.

Additional information
It looks like the user portal is behind a login, it may be that the API requires user credentials to access - to investigate.

This is also a UK portal so may want to see if we can filter down to Scotland level, or, datasets containing Scottish data. Or see https://scotland.nbnatlas.org