message: doc(util/profile): polish
diff: +//! # An internal profiler for Cargo itself
  +//!
  +//! > **Note**: This might not be the module you are looking for.
  +//! > For information about how Cargo handles compiler flags with profiles,
  +//! > please see the module [`cargo::core::profiles`](crate::core::profiles).
  +
  use std::cell::RefCell;
  use std::env;
  use std::fmt;
  