Switch changelog "unreleased" to today. (#24)

Switch changelog unrelease to today.

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Unreleased
+## [1.1.0] - 2024-08-03
 
 - Changed error message when attempting to await a non-awaitable object (*i.e.*, it has no `__await__`).
 - Fixed coroutine iterator reference leak.