Documentation: Dead link to OLS

[hansenp]

This section of the documentation links to the Ontology Lookup Service (OLS):
https://obophenotype.github.io/upheno/reference/core-concepts/

The link behind the text "Unified Phenotype Ontology (uPheno)" is as follows:
https://www.ebi.ac.uk/ols4/ontologies/upheno

After clicking you will be redirected to:
https://www.ebi.ac.uk/ols4/error

UPHENO is not included in OLS4.

[matentzn]

Thank you!

I have fixed this for now by linking to: https://ols.monarchinitiative.org/ontologies/upheno2

I will keep the issue open though because we really need to load the correct uPheno2 into OLS -proper.