feat: prepare VS Code extension for marketplace

editors/vscode/CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 0.2.1
+
+- Prepared the extension manifest, branding, documentation, and PNG icon for the
+  Visual Studio Marketplace.
+- Added repeatable build, validation, packaging, and publishing instructions.
+- Documented formatter setup and the extension's no-telemetry policy.
+
 ## 0.2.0
 
 - Added native Format Document and format-on-save support for `.wrn` files.