chore: adapt changelog for 0.14.0 (#215)

Updated version number and release date for 0.14.0. Modified changelog
sections to reflect recent changes.

Author: johannes-vogel

CHANGELOG.md

@@ -5,9 +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/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## Version 0.14.0 - tbd
-
-### Added
+## Version 0.14.0 - 2025-10-24
 
 ### Changed
 
@@ -19,8 +17,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Read GraphiQL HTML file only once on startup, and only if GraphiQL is enabled, to avoid unnecessary file system access
 - Server crash by `SyntaxError` from express JSON parser
 
-### Removed
-
 ## Version 0.13.0 - 2025-07-11
 
 ### Added