message: doc(interface-types) Improve `serde` module documentation.
diff: //! Serde is not necessary to use WIT. It only provides a nicer API
  -//! for the end-user to rebuild its complex types from WIT values,
  -//! like `record`.
  +//! for the end-user to send or receive its complex types to/from WIT
  +//! values, like `record` for instance.
  use crate::{
  ast::InterfaceType,
  