Implement pass-otp compatible TOTP and HOTP

README.md

@@ -33,6 +33,8 @@ bounded caching are documented in
 [`docs/secure-secret-storage.md`](docs/secure-secret-storage.md).
 Clipboard cleanup/race behavior and platform-neutral QR rendering are
 documented in [`docs/presentation.md`](docs/presentation.md).
+Pass-OTP URI compatibility, RFC code generation, and atomic HOTP counters are
+documented in [`docs/otp.md`](docs/otp.md).
 The capability-scoped password-store layout and atomic mutation guarantees are
 documented in [`docs/repository-core.md`](docs/repository-core.md).
 The embedded OpenPGP backend, exported-key model, secret-provider boundary, and