Add compile requirements from iced.

Mostly to require documentation, but provides a few other
requirements to be consistant with upstream.

Author: 13r0ck

src/lib.rs

@@ -1,3 +1,19 @@
+#![doc(
+    html_logo_url = "https://raw.githubusercontent.com/iced-rs/iced/9ab6923e943f784985e9ef9ca28b10278297225d/docs/logo.svg"
+)]
+#![deny(
+    missing_debug_implementations,
+    missing_docs,
+    unused_results,
+    clippy::extra_unused_lifetimes,
+    clippy::from_over_into,
+    clippy::needless_borrow,
+    clippy::new_without_default,
+    clippy::useless_conversion
+)]
+#![forbid(unsafe_code, rust_2018_idioms)]
+#![allow(clippy::inherent_to_string, clippy::type_complexity)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 pub mod timeline;
 pub mod widget;