Update appveyor.yml

Author: josesimoes

appveyor.yml

@@ -135,7 +135,7 @@ for:
   - provider: GitHub
     tag: v$(MyNuGetVersion)
     release: nanoFramework Core Library v$(MyNuGetVersion)
-    description: 'Check the [changelog](https://github.com/nanoframework/lib-CoreLibrary/blob/develop/CHANGELOG.md)\n\n## Install from nanoFramework MyGet development feed\n\nThe following NuGet packages are available for download from this release\n\npackage: [.NET](https://www.myget.org/feed/nanoframework-dev/package/nuget/nanoFramework.CoreLibrary/$(MyNuGetVersion)) v$(MyNuGetVersion)'
+    description: 'Check the [changelog](https://github.com/nanoframework/lib-CoreLibrary/blob/develop/CHANGELOG.md)\n\n## Install from nanoFramework MyGet development feed\n\nThe following NuGet packages are available for download from this release\n\n:package: [.NET](https://www.myget.org/feed/nanoframework-dev/package/nuget/nanoFramework.CoreLibrary/$(MyNuGetVersion)) v$(MyNuGetVersion)'
     auth_token:
       secure: DNixoFFE+pGlwyhj7McfZoln42vOmj0iY1iNV9zXEr3y0NpXlOIgL8k5ehzlFM1S
     artifact: source\Nuget.CoreLibrary\bin\Release\nanoFramework.CoreLibrary.$(MyNuGetVersion).nupkg