Add changelog file

Author: leadpony

CHANGELOG.md

@@ -0,0 +1,10 @@
+# Changelog
+
+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).
+
+## v0.1.0 - 2026-01-02
+### Added
+- Initial release

README.md

@@ -1,5 +1,7 @@
 # slogan
 
+[![Documentation](https://godoc.org/github.com/openclosed-dev/slogan?status.svg)](https://godoc.org/github.com/openclosed-dev/slogan/appinsights) [![Release](https://img.shields.io/github/release/openclosed-dev/slogan/all.svg)](https://github.com/openclosed-dev/slogan/releases)
+
 slogan is a [slog](https://pkg.go.dev/log/slog) Handler for submitting log records to [Azure Application Insights](https://learn.microsoft.com/en-us/azure/azure-monitor/app/app-insights-overview).
 
 ## Prerequisites