Pet allowed as well as putting up pictures

The contract has been generated not allowing a pet or putting up pictures. I did allow pets in my advert and am ok with the tenant having her dog living in the house. I’m also ok with pictures being put up if done without damaging the walls and that the holes are made good at the end of the tenancy. Can anyone please help by suggesting clauses that can be added to the contract to allow tenants to do these?

Thank you