💰Burn $PEPAY

When a user burns (sells to contract) $PEPAY, the $PEPAY tokens are burned, and the $PEPE is returned to the user based on the current backing ratio (which can only go up over time.)

Result: $PEPAY Vault increases, the backing price goes up in $PEPE. $1 in $PEPAY is burned but $.90 in $PEPE is returned, so that the backing increases more than the token inflation.