fix(identity): build with all features on docs.rs

Resolves #3810.

Pull-Request: #3828.

identity/Cargo.toml

@@ -49,3 +49,10 @@ criterion = "0.4"
 [[bench]]
 name = "peer_id"
 harness = false
+
+# Passing arguments to the docsrs builder in order to properly document cfg's.
+# More information: https://docs.rs/about/builds#cross-compiling
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+rustc-args = ["--cfg", "docsrs"]

identity/src/lib.rs

@@ -33,6 +33,8 @@
 //! (e.g. [ed25519 binary format](https://datatracker.ietf.org/doc/html/rfc8032#section-5.1.5)).
 //! All key types have functions to enable conversion to/from their binary representations.
 
+#![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
+
 #[cfg(any(
     feature = "ecdsa",
     feature = "secp256k1",