Update wiki SPARQL API example to explain use of kb-2 graph
Created by: brianjlowe
Prompted by https://github.com/vivo-project/VIVO/issues/3900
The SPARQL UPDATE wiki page at https://wiki.lyrasis.org/display/VIVODOC113x/SPARQL+Update+API uses the http://vitro.mannlib.cornell.edu/default/vitro-kb-2 graph in its examples but doesn't explain why this particular graph IRI is significant. It should be updated with a brief but prominent explanation of the fact that kb-2 is the only graph from which the GUI editor is able to remove triples, so data that is intended to be manually edited should be loaded here.