[ENHANCEMENT] add LicenceURL

[4tikhonov]

Please elaborate here on the enhancement request.
In the Licence section of the document LICENCE file is present is readable for human however Licence URL should be also part of it to increase the interoperability and allow machine-to-machine interaction. Currently F-UJI FAIR assestment tool check if licenceURL is present in SPDX list of licences https://github.com/pangaea-data-publisher/fuji/blob/master/fuji_server/data/licenses.json

Describe the solution you'd like
Probably we need to add LicenceURL in section 4.4 of the document.

[mariojmdavid]

solved in devel

[mariojmdavid]

release v4.1