Check and add more SPARQL endpoints

[vemonet]

List here: https://github.com/OpenLinkSoftware/general-turtle-doc-collection/blob/master/LODCloud_SPARQL_Endpoints.ttl

We could also parse it automatically

Biomedical SPARQL: https://yummydata.org/

[vemonet]

Biomedical endpoints: https://jbiomedsem.biomedcentral.com/articles/10.1186/s13326-016-0079-8#Abs1

such as UniProt, DisGeNet [30], Protein Data Bank Japan (PDBj) [17], and EBI resources such as Gene Expression Atlas [31], ChEMBL [32], BioModels [33], Reactome [34], and BioSamples [35]