Colored code snippet in markdown

[akordowski]

Hello! I would like to have colored code snippets in the final documentation. I tried it like described here but it don't work. I am using the version 2.77.0.

The following markdown content is rendered like this:

[!code-csharp[]]
```csharp
host.ConfigureAppConfiguration(config =>
    {
        config.AddJsonFile("appsettings.json", true);
    })
    .ConfigureServices((context, services) =>
    {
        services.AddMethod(context.Configuration);
    });
```

Have anyone an idea what I'm making wrong? Any help is appreciated. Thanks in advance.