This release adds a new getSigner method that can be used with an address to get a signer object for that address:
const signer = await ethers.getSigner("0xabc...");Of course, this signer can be used for writing only if that address is unlocked. Otherwise it can be used in a read-only fashion.
This release also fixes getContractAt so that, if there are no signers available, you still get a contract instance that can only be used for read operations.
Finally, it's now possible for a typescript plugin to declare which methods are added to the ethers object.