Generate doc for lua_module macro using doc cfg instead of docsrs

Author: khvzak

Cargo.toml

@@ -36,7 +36,7 @@ luau = ["ffi/luau", "dep:libloading"]
 luau-jit = ["luau", "ffi/luau-codegen"]
 luau-vector4 = ["luau", "ffi/luau-vector4"]
 vendored = ["ffi/vendored"]
-module = ["dep:mlua_derive", "ffi/module"]
+module = ["mlua_derive", "ffi/module"]
 async = ["dep:futures-util"]
 send = ["parking_lot/send_guard", "error-send"]
 error-send = []

src/lib.rs

@@ -247,7 +247,7 @@ pub use mlua_derive::FromLua;
 ///     ...
 /// }
 /// ```
-#[cfg(any(feature = "module", docsrs))]
+#[cfg(all(feature = "mlua_derive", any(feature = "module", doc)))]
 #[cfg_attr(docsrs, doc(cfg(feature = "module")))]
 pub use mlua_derive::lua_module;