chore: rm doc_auto_cfg (#75)

Author: onbjerg

src/lib.rs

@@ -1,6 +1,6 @@
 #![doc = include_str!("../README.md")]
 #![cfg_attr(not(test), warn(unused_crate_dependencies))]
-#![cfg_attr(docsrs, feature(doc_cfg, doc_auto_cfg))]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 #[macro_use]
 extern crate tracing;