Show all modules on docs.rs

Add docs feature to docs.rs metadata
see https://github.com/onur/docs.rs/pull/73

Author: the8472

Cargo.toml

@@ -14,6 +14,9 @@ description = """
 CPUs, as well as raw interfaces to platform-specific instructions.
 """
 
+[package.metadata.docs.rs]
+features = ["doc"]
+
 [dependencies]
 serde = { version = "1.0", optional = true }
 serde_derive = { version = "1.0", optional = true }