Add feature indicators to docs.rs documentation

Shows what feature must be enabled for each method to be available

Cargo.toml

@@ -51,3 +51,7 @@ unexpected_cfgs = { level = "deny", check-cfg = ['cfg(oneshot_loom)', 'cfg(onesh
 [[bench]]
 name = "benches"
 harness = false
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]

src/lib.rs

@@ -115,6 +115,9 @@
 
 #![deny(rust_2018_idioms)]
 #![cfg_attr(not(feature = "std"), no_std)]
+// Enables this nightly only feature for the documentation build on docs.rs.
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 
 #[cfg(not(oneshot_loom))]
 extern crate alloc;