Add rustdoc header to the struct constructors

Otherwise it triggers the missing_docs warning on dependent projects

Signed-off-by: Alejandro G. Vallejo <[email protected]>

bilge-impl/src/bitsize_internal.rs

@@ -74,6 +74,7 @@ fn generate_struct(struct_data: &ItemStruct, arb_int: &TokenStream) -> TokenStre
         impl #ident {
             // #[inline]
             #[allow(clippy::too_many_arguments, clippy::type_complexity, unused_parens)]
+            /// Create a struct from its constituents
             pub #const_ fn new(#( #constructor_args )*) -> Self {
                 type ArbIntOf<T> = <T as Bitsized>::ArbitraryInt;
                 type BaseIntOf<T> = <ArbIntOf<T> as Number>::UnderlyingType;