fix categories URL helper
fix categories URL helper

rtluu/immersive,basemm911/questionsociety,dominictracey/Telescope,manriquef/Vulcan,manriquef/Vulcan,jonmc12/heypsycho,Discordius/Telescope,johndpark/Telescope,JstnEdr/Telescope,acidsound/Telescope,aichane/digigov,Discordius/Lesswrong2,VulcanJS/Vulcan,ahmadassaf/Telescope,Air2air/Telescope,rtluu/immersive,aichane/digigov,Discordius/Lesswrong2,dominictracey/Telescope,nathanmelenbrink/theRecord,bengott/Telescope,JstnEdr/Telescope,HelloMeets/HelloMakers,Discordius/Telescope,dominictracey/Telescope,TodoTemplates/Telescope,HelloMeets/HelloMakers,SachaG/Zensroom,acidsound/Telescope,Discordius/Lesswrong2,huaiyudavid/rentech,basemm911/questionsociety,ahmadassaf/Telescope,bengott/Telescope,julienlapointe/telescope-nova-social-news,TodoTemplates/Telescope,bshenk/projectIterate,huaiyudavid/rentech,SachaG/Gamba,Discordius/Lesswrong2,Discordius/Telescope,bshenk/projectIterate,Air2air/Telescope,basemm911/questionsociety,aichane/digigov,Air2air/Telescope,SachaG/Zensroom,TodoTemplates/Telescope,HelloMeets/HelloMakers,julienlapointe/telescope-nova-social-news,bengott/Telescope,SachaG/Zensroom,ahmadassaf/Telescope,johndpark/Telescope,nathanmelenbrink/theRecord,jonmc12/heypsycho,SachaG/Gamba,huaiyudavid/rentech,VulcanJS/Vulcan,johndpark/Telescope,jonmc12/heypsycho,julienlapointe/telescope-nova-social-news,rtluu/immersive,acidsound/Telescope,manriquef/Vulcan,nathanmelenbrink/theRecord,JstnEdr/Telescope,bshenk/projectIterate,Discordius/Telescope,SachaG/Gamba