message: docs(upgrade): fix typo in upgrade docs
diff: //!
  //! # Client
  //!
  -//! Sending an HTTP ugprade from the [`client`](super::client) involves setting
  +//! Sending an HTTP upgrade from the [`client`](super::client) involves setting
  //! either the appropriate method, if wanting to `CONNECT`, or headers such as
  //! `Upgrade` and `Connection`, on the `http::Request`. Once receiving the
  //! `http::Response` back, you must check for the specific information that the
  