[docs] added info about reistogo to readme
[docs] added info about reistogo to readme

hacor/pkgcloud,dionjwa/pkgcloud,temka1234/pkgcloud,mdsummers/pkgcloud,apla/pkgcloud,Phanatic/pkgcloud,mcanthony/pkgcloud,Hopebaytech/pkgcloud,songanbui/pkgcloud,bunglestink/pkgcloud,andrewsomething/pkgcloud,Phanatic/pkgcloud,pkgcloud/pkgcloud,DonSchenck/pkgcloud