[to squash] remove some old doccomments from consensus_encoding

diff --git a/consensus_encoding/src/lib.rs b/consensus_encoding/src/lib.rs
index aa0f6bf9..6ea4435f 100644
--- a/consensus_encoding/src/lib.rs
+++ b/consensus_encoding/src/lib.rs
@@ -5,15 +5,6 @@
 //! This library provides traits that can be used to encode/decode objects in a
 //! consensus-consistent way.
 //!
-//! ## Notes on I/O
-//!
-//! I/O in Rust has a few problems in relation to no-std, as such we depend on the [`bitcoin-io`]
-//! crate and this library uses `io::Read` and `io::Write` to read and write respectively to readers
-//! and writers that are, to the best of our ability, interoperable with `std::io`. This includes
-//! error handling by way of the [`bitcoin_io::Error`].
-//!
-//! [bitcoin-io]: io
-//! [`bitcoin_io::Error`]: io::Error
 
 #![no_std]
 // Experimental features we need.
@@ -22,11 +13,3 @@
 #![warn(missing_docs)]
 #![warn(deprecated_in_future)]
 #![doc(test(attr(warn(unused))))]
-// Exclude lints we don't think are valuable.
-#![allow(clippy::uninlined_format_args)] // Allow `format!("{}", x)`instead of enforcing `format!("{x}")`
-
-#[cfg(feature = "alloc")]
-extern crate alloc;
-
-#[cfg(feature = "std")]
-extern crate std;