Fixed updated docs to match the 80 column style the rest of the docs use
//! features = ["tokio02"]
//! ```
//!
-//! Compatibility with the `tokio` 0.3 runtime is also simultaneously possible using the `tokio03`
-//! Cargo feature:
+//! Compatibility with the `tokio` 0.3 runtime is also simultaneously possible
+//! using the `tokio03` Cargo feature:
//!
//! ```toml
//! [dependencies.async-std]
