Add Rails 5 API controller template for the controller generator
user
```ruby
<% if namespaced? -%>
require_dependency "<%= namespaced_file_path %>/application_controller"

<% end -%>
<% module_namespacing do -%>
class <%= controller_class_name %>Controller < ApplicationController
  before_action :set_<%= singular_table_name %>, only: [:show, :update, :destroy]

  respond_to :json

<% unless options[:singleton] -%>
  def index
    @<%= plural_table_name %> = <%= orm_class.all(class_name) %>
    respond_with(@<%= plural_table_name %>)
  end
<% end -%>

  def show
    respond_with(@<%= singular_table_name %>)
  end

  def create
    @<%= singular_table_name %> = <%= orm_class.build(class_name, attributes_params) %>
    <%= "flash[:notice] = '#{class_name} was successfully created.' if " if flash? %>@<%= orm_instance.save %>
    respond_with(@<%= singular_table_name %>)
  end

  def update
    <%= "flash[:notice] = '#{class_name} was successfully updated.' if " if flash? %>@<%= orm_instance.update(attributes_params) %>
    respond_with(@<%= singular_table_name %>)
  end

  def destroy
    @<%= orm_instance.destroy %>
    respond_with(@<%= singular_table_name %>)
  end

  private
    def set_<%= singular_table_name %>
      @<%= singular_table_name %> = <%= orm_class.find(class_name, "params[:id]") %>
    end

    def <%= "#{singular_table_name}_params" %>
      <%- if attributes_names.empty? -%>
      params[:<%= singular_table_name %>]
      <%- else -%>
      params.require(:<%= singular_table_name %>).permit(<%= attributes_names.map { |name| ":#{name}" }.join(', ') %>)
      <%- end -%>
    end
end
<% end -%>
```
assistant