Reduce output HTML

[attakei]

What do you need?

I use include directive to split contents of presentation.
I don't need outpiut html files of included sources, but builder generate them.

Example

+ presentation/
  + index.rst
  + _introduction.rst

index.rst:

=====
Title
=====

.. include:: _introduction.rst

Expected outputs

+ BUILD/
  + presentation.html

Actually outputs

+ BUILD/
  + presentation.html
  + _introduction.html