Add example to crate root

src/lib.rs

@@ -8,6 +8,20 @@
 //! map one-to-one to the HTTP API's JSON input- and response data. Using the `ListenBrainz`
 //! type is therefore recommended.
 //!
+//! # Example
+//!
+//! ```no_run
+//! # use listenbrainz::ListenBrainz;
+//! #
+//! let mut client = ListenBrainz::new();
+//!
+//! client.authenticate("LISTENBRAINZ TOKEN")
+//!     .expect("Could not authenticate with ListenBrainz");
+//!
+//! client.playing_now("The Beatles", "Here Comes the Sun", "Abbey Road")
+//!     .expect("Could not submit 'playing now' request");
+//! ```
+//!
 //! [ListenBrainz HTTP API]: https://listenbrainz.readthedocs.io/en/production/dev/api/
 
 mod error;