The current upgrade-able contract docs guide is based around the [TransparentUpgradeableProxy](https://docs.openzeppelin.com/contracts/5.x/api/proxy#TransparentUpgradeableProxy) pattern: https://hardhat.org/ignition/docs/guides/upgradeable-proxies We should add a guide for the [Universal Upgradeable Proxy Standard pattern](https://eips.ethereum.org/EIPS/eip-1822). See the Open Zeppelin docs for a description of the difference: https://docs.openzeppelin.com/contracts/4.x/api/proxy#transparent-vs-uups