Add unreleased section to the changelog

Author: link2xt

CHANGELOG.md

@@ -5,6 +5,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Changed
+
+- Do not generate artificial "broken pipe" errors when attempting to send a request
+  after reaching EOF on the response stream. #73
+
 ## [0.7.0] - 2023-04-03
 
 ### Added