Implementation of the libp2p `Transport` trait for TCP/IP.
# Usage
This crate provides two structs, `TcpConfig` and `TokioTcpConfig`, depending on which
features are enabled.
Both the `TcpConfig` and `TokioTcpConfig` structs implement the `Transport` trait of the
`core` library. See the documentation of `core` and of libp2p in general to learn how to
use the `Transport` trait.