Simple example to export the `ContentTypeDefinition`

ExampleDefinitions.cs

using System.ComponentModel.Composition;
using Microsoft.VisualStudio.Utilities;

public static class ExampleDefinitions
{
    /* The language name (used for the language service) and content type must be the same
     * due to the way Visual Studio internally registers file extensions and content types.
     */
    [Export]
    [Name("Example")]
    [BaseDefinition("code")]
    private static readonly ContentTypeDefinition ExampleContentTypeDefinition;
}