code: func (s GitignoresService) List(ctx context.Context) ([]string, *Response, error) {
  	req, err := s.client.NewRequest("GET", "gitignore/templates", nil)
  	if err != nil {
  		return nil, nil, err
  	}
  
  	var availableTemplates []string
  	resp, err := s.client.Do(ctx, req, &availableTemplates)
  	if err != nil {
  		return nil, resp, err
  	}
  
  	return availableTemplates, resp, nil
  }
docs: // List all available Gitignore templates.
  //
  // GitHub API docs: https://developer.github.com/v3/gitignore/#listing-available-templates