The generator plugin test CustomPlugins.TagDecoratorGeneratorPlugin.Test needs to load the plugin from NuGet package. But the package is not published, so we have a nuget.config file to add the bin\Debug folder of the plugin to the NuGet package sources.
Important: In order to load the latest version of the plugin, you need to remove the plugin from your local NuGet package cache, C:\Users\<your-user-name>\.nuget\packages\customplugins.tagdecoratorgeneratorplugin, otherwise the old version will be loaded.