updated Store API docstrings
updated Store API docstrings

yingerj/rdflib,dbs/rdflib,avorio/rdflib,armandobs14/rdflib,marma/rdflib,ssssam/rdflib,marma/rdflib,yingerj/rdflib,yingerj/rdflib,avorio/rdflib,marma/rdflib,ssssam/rdflib,RDFLib/rdflib,RDFLib/rdflib,armandobs14/rdflib,RDFLib/rdflib,dbs/rdflib,marma/rdflib,yingerj/rdflib,avorio/rdflib,RDFLib/rdflib,armandobs14/rdflib,armandobs14/rdflib,dbs/rdflib,avorio/rdflib,ssssam/rdflib,dbs/rdflib,ssssam/rdflib