These have been deprecated for a while. The same functionality is covered by: - `atproto/identity`: DID resolution and parsing - `atproto/atcrypto`: cryptographic keys - https://github.com/did-method-plc/did-method-plc: creating and verifying DID PLC operations The one piece of dropped functionality here was the ability for `gosky` to generate PLC operations and submit them to the directory. Currently the `go-didplc` package depends on `indigo` (for crypto and syntax packages), and I don't want to create a dependency loop (even if it isn't a package-level dependency loop). Also the `goat plc ...` commands support this functionality (using the `go-didplc` package). This is part of general cleanups.