Change controller type name

Using the following code:

```csharp
class SomethingController : GraphController {
  [Mutation]
  public async Task<IGraphActionResult> Create() {
    return Ok(...);
  }
}
```

The type name of the root mutation `something` becomes `Mutation_Something`.

I was wondering if the name of this type can be changed. I couldn't find anything about this in de docs so far.