Hide documentation of the Unpin implementation for !Unpin (#355)

Author: matheus-consoli

pin-project-internal/src/pin_project/derive.rs

@@ -718,6 +718,7 @@ fn make_unpin_impl(cx: &Context<'_>) -> TokenStream {
             // call-site span.
             let unsafety = <Token![unsafe]>::default();
             quote_spanned! { span =>
+                #[doc(hidden)]
                 impl #proj_impl_generics _pin_project::__private::Unpin
                     for #orig_ident #ty_generics
                 #proj_where_clause

tests/expand/not_unpin/enum.expanded.rs

@@ -114,6 +114,7 @@ const _: () = {
             }
         }
     }
+    #[doc(hidden)]
     impl<'pin, T, U> _pin_project::__private::Unpin for Enum<T, U>
     where
         _pin_project::__private::Wrapper<

tests/expand/not_unpin/struct.expanded.rs

@@ -74,6 +74,7 @@ const _: () = {
         let _ = &this.pinned;
         let _ = &this.unpinned;
     }
+    #[doc(hidden)]
     impl<'pin, T, U> _pin_project::__private::Unpin for Struct<T, U>
     where
         _pin_project::__private::Wrapper<

tests/expand/not_unpin/tuple_struct.expanded.rs

@@ -68,6 +68,7 @@ const _: () = {
         let _ = &this.0;
         let _ = &this.1;
     }
+    #[doc(hidden)]
     impl<'pin, T, U> _pin_project::__private::Unpin for TupleStruct<T, U>
     where
         _pin_project::__private::Wrapper<