chore: Fix rustdoc lints

src/lib.rs

@@ -1,3 +1,4 @@
+#![allow(rustdoc::invalid_html_tags)]
 //! # Async version of the Rust standard library
 //!
 //! `async-std` is a foundation of portable Rust software, a set of minimal and battle-tested

src/task/block_on.rs

@@ -19,11 +19,9 @@ use crate::task::Builder;
 /// ```no_run
 /// use async_std::task;
 ///
-/// fn main() {
 /// task::block_on(async {
 ///     println!("Hello, world!");
 /// })
-/// }
 /// ```
 #[cfg(not(target_os = "unknown"))]
 pub fn block_on<F, T>(future: F) -> T