Update Avalonia.Controls.PanAndZoom.csproj

src/Avalonia.Controls.PanAndZoom/Avalonia.Controls.PanAndZoom.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>netstandard2.0;net6.0;net8.0</TargetFrameworks>
     <OutputType>Library</OutputType>
     <DocumentationFile>bin\$(Configuration)\$(TargetFramework)\$(AssemblyName).xml</DocumentationFile>
     <Nullable>enable</Nullable>