Typings: make name optional in NodeTypeAnnotation

[sloonz]

The type for NodeTypeAnnotation is :

export interface NodeTypeAnnotations {    
  /** The type annotation of the Node */    
  name: string;    
  /** The type annotations of the {@link https://github.com/kdl-org/kdl/blob/main/SPEC.md#argument|Arguments} */    
  values: string[];    
  /** The type annotations of the {@link https://github.com/kdl-org/kdl/blob/main/SPEC.md#property|Properties} */    
  properties: Record<string, string>;    
}

However, name can be undefined.