Add CHANGELOG for ruby-4.0

Author: larskanis

CHANGELOG-4.0.md

@@ -0,0 +1,10 @@
+## RubyInstaller-4.0.0-1 - 2025-12-27
+
+This is the first release based on ruby-4.0.x: https://www.ruby-lang.org/en/news/2025/12/25/ruby-4-0-0-released/
+
+### Changes compared to [RubyInstaller-3.4.8-1](CHANGELOG-3.4.md#rubyinstaller-348-1---2025-12-18)
+
+- Shrink the 5 app icons to only one and a subsequent console-based startmenu.
+  One icon only is a requirement of Microsoft to provide an app in the Microsoft Store.
+- Add a patch to fix ruby's CLI to recognize inputs as UTF-8
+  https://github.com/ruby/ruby/pull/12377