message: extend doc comment
diff: @@ -140,10 +140,10 @@ where
  /// expand into a trait and a set of structs, one per query.
  ///
  /// For each query, you give the name of the accessor method to invoke
  -/// the query (e.g., `my_query`, below), as well as its input/output
  -/// types. You also give the name for a query type (e.g., `MyQuery`,
  -/// below) that represents the query, and optionally other details,
  -/// such as its storage.
  +/// the query (e.g., `my_query`, below), as well as its parameter
  +/// types and the output type. You also give the name for a query type
  +/// (e.g., `MyQuery`, below) that represents the query, and optionally
  +/// other details, such as its storage.
  ///
  /// ### Examples
  ///
  @@ -158,6 +158,12 @@ where
  /// storage memoized; // optional, this is the default
  /// use fn path::to::fn; // optional, default is `my_query`
  /// }
  +///
  +/// /// Queries can have any number of inputs; the key type will be
  +/// /// a tuple of the input types, so in this case `(u32, f32)`.
  +/// fn other_query(input1: u32, input2: f32) -> u64 {
  +/// type OtherQuery;
  +/// }
  /// }
  /// }
  /// ```
  