examples/chat-tokio: Fix run example feature
//! The example is run per node as follows:
//!
//! ```sh
-//! cargo run --example chat-tokio --features="tcp-tokio mdns-tokio"
+//! cargo run --example chat-tokio --features="tcp-tokio mdns"
//! ```
//!
//! Alternatively, to run with the minimal set of features and crates:
//! ```sh
//!cargo run --example chat-tokio \\
//! --no-default-features \\
-//! --features="floodsub mplex noise tcp-tokio mdns-tokio"
+//! --features="floodsub mplex noise tcp-tokio mdns"
//! ```
use libp2p::{
