Poetry update, update changelog

Author: pappasam

CHANGELOG.md

@@ -4,6 +4,17 @@ 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).
 
+## 0.40.0
+
+### Added
+
+- Diagnostic support using Python's builtin `compile` function.
+
+### Changed
+
+- `pygls` 1.0!
+- Diagnostics (for syntax errors) are once-again enabled by default.
+
 ## 0.39.0
 
 ### Changed