Documented needed crate feature

Author: rodrimati1992

src/distributions/other.rs

@@ -186,6 +186,7 @@ tuple_impl! {A, B, C, D, E, F, G, H, I, J}
 tuple_impl! {A, B, C, D, E, F, G, H, I, J, K}
 tuple_impl! {A, B, C, D, E, F, G, H, I, J, K, L}
 
+#[cfg_attr(doc_cfg, doc(cfg(feature = "min_const_gen")))]
 #[cfg(feature = "min_const_gen")]
 impl<T, const N: usize> Distribution<[T; N]> for Standard
 where Standard: Distribution<T>