Update CHANGELOG for v1.0.0 release (#8)

Update CHANGELOG for v1.0.0 release

Author: balgillo

CHANGELOG.md

@@ -4,6 +4,15 @@ 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).
 
+## [1.0.0](releases/tag/v1.0.0) - 2022-05-09
+
+### Changed
+- Development, build and release is now based on [python-poetry](https://python-poetry.org).
+- No change to functionality since v0.3.0.
+
+### Compatibility
+- Python 3.8+
+
 ## [0.3.0](releases/tag/v0.3.0) - 2022-01-14
 
 ### Added

CONTRIBUTING.md

@@ -28,6 +28,8 @@ Pull requests are welcome.
 
 - You need Python 3.8 installed.
   - This is the minimum supported version of the tool.  Developing with a later version risks introducing type hints such as `list[dict]` that are not compatible with Python 3.8.
+- You need Poetry installed.  Run this in an Admin CMD or under `sudo`:
+  - `pip install poetry`
 
 Initialise Poetry by telling it where Python 3.8 is, e.g.