message: docs: Fix documentation
  This seems extraneous.
diff: //!
  //! An [`Event`] represents a _moment_ in time. It signifies something that
  //! happened while a trace was being recorded. `Event`s are comparable to the log
  -//! records emitted by unstructured logging code, but unlike a typical log line,``s
  +//! records emitted by unstructured logging code, but unlike a typical log line,
  //! an `Event` may occur within the context of a span.
  //!
  //! For example:
  