Add Brockmann Consult GmbH as provider and the EFAST UDP

[Hneuschmidt]

Follow-up to #295 and #303

[Hneuschmidt]

The UDP description has been updated in the UDP repo. This should address your comments (@JanssenBrm) #303 . Thumbnail is still missing, can be added later.

[Hneuschmidt]

I have updated the rel types of the newly added links.
For the example notebook, I have found only one example in the repository, which uses rel type "notebook":

apex_algorithms/algorithm_catalog/vito/parcel_delineation/records/parcel_delineation.json

Line 145 in 4e4372d

"rel": "notebook",

I have made the same choices as in this example, using

"type": "text/html"

and a link to the raw notebook json file.

Please let me know if it would be preferable to use the mime type application/x-ipynb+json, as used by the jupyter project itself [1], or to link to the github page containing the notebook, which renders it in a suitable way for viewing in a browser.

[1]: https://docs.jupyter.org/en/latest/reference/mimetype.html