runtime: update doc regarding `runtime::run` function helper
//! boilerplate to run a Tokio application.
//!
//! Most applications wont need to use [`Runtime`] directly. Instead, they will
-//! use the [`run`] function, which uses [`Runtime`] under the hood.
+//! use the [`tokio::main`] attribute macro, which uses [`Runtime`] under the hood.
//!
//! Creating a [`Runtime`] does the following:
//!
