New decorator, `@SwaggerCustomizer()`

[samchon]

export function SwaggerCustomizer(
  closure: (props: SwaggerCustomizer.IProps) => unknown,
): MethodDecorator;
export namespace SwaggerCustomizer {
  export interface IProps {
    swagger: ISwagger;
    method: string;
    path: string;
    route: ISwaggerRoute;
    get(p: { path: string; method: string }): ISwaggerRoute | null;
  }
}

Will add a new decorator which can customize the Swagger Documents.