Add example of OWL expression

[wdahdul]

In the documentation, please add an example of an OWL expression used to query entities

[hlapp]

@wdahdul can you remind me which query this is for. OntoTrace?

[wdahdul]

Yes, for OntoTrace queries using owl expressions (which currently doesn't work, see #14)

[hlapp]

This is now added to the documentation in the upcoming v0.3.0 release:

# query using taxon and/or entity owl expressions resolved from label expressions
taxon_owl <- as.owl("Ictalurus", usesLabels = TRUE)
entity_owl <- as.owl("'fin' or ('part of' some 'fin')", usesLabels = TRUE)
nex <- get_ontotrace_data(taxon = taxon_owl, entity = entity_owl)