chore(pkg-py): v0.1.0 release candidate (#90)

* v0.1.0 release candidate

* Tidy up wording

* Update pkg-py/CHANGELOG.md

Author: cpsievert

pkg-py/CHANGELOG.md

@@ -5,9 +5,6 @@ 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]
+## [0.1.0] - 2025-08-07
 
-* The `shinychat` package was created from the `shiny.ui.Chat` and
-  `shiny.ui.MarkdownStream` components as a new package. These components will
-  still be available in the `shiny` package, but by separating the `shinychat`
-  package we can more easily maintain and develop these components independently with a faster release cycle.
+This first release of the `shinychat` package simply copies the `Chat` and `MarkdownStream` components exactly as they are in version 1.4.0 of `shiny`. Future versions of `shiny` will import these components from `shinychat`. By maintaining these components via a separate library, we can ship features more quickly and independently of `shiny`.