Add docs for SimpleFS plugin
Add docs for SimpleFS plugin

dietsche/letsencrypt,Sveder/letsencrypt,wteiken/letsencrypt,mitnk/letsencrypt,twstrike/le_for_patching,ghyde/letsencrypt,mrb/letsencrypt,kuba/letsencrypt,martindale/letsencrypt,hsduk/lets-encrypt-preview,letsencrypt/letsencrypt,bsmr-misc-forks/letsencrypt,piru/letsencrypt,mrb/letsencrypt,DavidGarciaCat/letsencrypt,letsencrypt/letsencrypt,thanatos/lets-encrypt-preview,stweil/letsencrypt,twstrike/le_for_patching,DavidGarciaCat/letsencrypt,TheBoegl/letsencrypt,hsduk/lets-encrypt-preview,VladimirTyrin/letsencrypt,ghyde/letsencrypt,BillKeenan/lets-encrypt-preview,piru/letsencrypt,jtl999/certbot,thanatos/lets-encrypt-preview,jsha/letsencrypt,lmcro/letsencrypt,jtl999/certbot,mitnk/letsencrypt,bsmr-misc-forks/letsencrypt,lbeltrame/letsencrypt,Sveder/letsencrypt,wteiken/letsencrypt,lmcro/letsencrypt,VladimirTyrin/letsencrypt,lbeltrame/letsencrypt,brentdax/letsencrypt,sjerdo/letsencrypt,martindale/letsencrypt,jsha/letsencrypt,xgin/letsencrypt,brentdax/letsencrypt,dietsche/letsencrypt,kuba/letsencrypt,goofwear/letsencrypt,TheBoegl/letsencrypt,sjerdo/letsencrypt,stweil/letsencrypt,xgin/letsencrypt,goofwear/letsencrypt,BillKeenan/lets-encrypt-preview