update docs for permalinks with all fields
update docs for permalinks with all fields

List all the fields and what they mean, based on hugolib/permalinks.go

tjyang/hugo,jygastaud/hugo,ifraixedes/hugo,tatsushid/hugo,vbatoufflet/hugo,ffrizzo/hugo,bramp/hugo,vbatoufflet/hugo,badoet/hugo,tjyang/hugo,kujohn/hugo,fhergomez/hugo,bogem/hugo,coderzh/hugo,abourget/hugo,halostatue/hugo,MarkDBlackwell/hugo,fedelibre/hugo,mayah/hugo,bramp/hugo,Zenithar/hugo,Zenithar/hugo,fedelibre/hugo,mitchchn/hugo,derekperkins/hugo,ffrizzo/hugo,bogem/hugo,mdhender/hugo,fedelibre/hugo,melo/hugo,badoet/hugo,anthonyfok/hugo,gohugoio/hugo,coderzh/hugo,fhergomez/hugo,soundrussian/hugo,mdhender/hugo,gohugoio/hugo,mdhender/hugo,jygastaud/hugo,anthonyfok/hugo,digitalcraftsman/hugo,mayah/hugo,tubo028/hugo,anthonyfok/hugo,ryanclarke/hugo,sprig/hugo,MarkDBlackwell/hugo,ryanclarke/hugo,mdhender/hugo,sprig/hugo,mitchchn/hugo,soundrussian/hugo,tischda/hugo,ifraixedes/hugo,derekperkins/hugo,kujohn/hugo,tatsushid/hugo,tubo028/hugo,fedelibre/hugo,digitalcraftsman/hugo,melo/hugo,halostatue/hugo,gohugoio/hugo,tischda/hugo,abourget/hugo