Run AutoStructify after Sphinx's Locale transform

[jpmckinney]

This is a better solution than #52

Note that you'd need to test on an unreleased version of commonmark.py to get this PR readthedocs/commonmark.py#225 and you'd need to have already merged #187, as otherwise translations are broken for other reasons.

[jpmckinney]

Nevermind – the problem is elsewhere (also, the code should, at least, have - 1 not + 1).

[jpmckinney]

Noting for posterity that the problem was that:

• reStructured Text within eval_rst blocks will be parsed as Markdown, after translation by the Locale transform.

• There is no way for it to be parsed as RST. The node would need to communicate its desired parser for that to work, but in any case Sphinx's publish_msgstr method and Locale transform look to to the document to determine the desired parser, not each node.

• To have complex content within an eval_rst block, it needs to instead be further embedded within a markdown block (from this module) and written as Markdown, e.g.

  .. note::
  
     .. markdown::
  
        A [link](http://example.com).
  
  

This will render, e.g. if translated to French, as "Un lien." within a note admonition.

On the other hand:

```eval_rst
.. note::

   A `link <http://example.com>`__.

will render, if translated to French, as "Un lien <http://example.com>__."