message: docs: add a parenthesis
  ## Motivation
  Looks like doc is missing a parenthesis
  ## Solution
  Add a parenthesis
diff: //! ```
  //!
  //! For functions which don't have built-in tracing support and can't have
  -//! the `#[instrument]` attribute applied (such as from an external crate,
  +//! the `#[instrument]` attribute applied (such as from an external crate),
  //! the [`Span` struct][`Span`] has a [`in_scope()` method][`in_scope`]
  //! which can be used to easily wrap synchonous code in a span.
  //!
  