make tabs invisible if there's only one
make tabs invisible if there's only one

pmacMaps/shortlist-storytelling-template-js,Esri/shortlist-storytelling-template-js,anarosner/storymap-shortlist-case-studies,anarosner/storymap-shortlist-case-studies,coreybaker/FoundationApp,Esri/shortlist-storytelling-template-js,regan-sarwas/shortlist-storytelling-template-js,pmacMaps/shortlist-storytelling-template-js,regan-sarwas/shortlist-storytelling-template-js