Update README.md

Preserve old version.

Author: HansOlsson

README.md

@@ -15,10 +15,10 @@ This library is inspired by Grafcet/Sequential Function Charts (SFC), Statechart
 Download [Modelica_StateGraph2 v2.0.5 (2020-04-02)](https://github.com/HansOlsson/Modelica_StateGraph2/releases/download/v2.0.5/Modelica_StateGraph2-release.zip)
 
 #### Release notes
-*  Version v2.0.5
+*  Version v2.0.5 (2020-04-02)
    * Some minor fixes. Be closer to standard Modelica and avoid problematic example.
-*  Version v2.0.4
-   * Uses Modelica Standard Library 3.2.3
+*  [Version v2.0.4](https://github.com/HansOlsson/Modelica_StateGraph2/releases/download/v2.0.4/Modelica_StateGraph2-release.zip)
+   * Uses Modelica Standard Library 3.2.3 
 *  Version v2.0.3
    * Uses Modelica Standard Library 3.2.2
 *  [Version v2.0.2 (2013-10-01)](../../archive/v2.0.2.zip)