[Docs] Added img for cookbook/theme R3
[Docs] Added img for cookbook/theme R3

pkarw/vue-storefront,DivanteLtd/vue-storefront,DivanteLtd/vue-storefront,pkarw/vue-storefront,pkarw/vue-storefront,DivanteLtd/vue-storefront,pkarw/vue-storefront,DivanteLtd/vue-storefront