DuneSphinxCMakeDoc
------------------

Generate CMake API documentation with Sphinx.

.. cmake:command:: dune_cmake_sphinx_doc

  Generate the buildsystem documentation from documented CMake modules.

  .. code-block:: cmake

    dune_cmake_sphinx_doc(
      [BUILDTYPE <type>...]
      [SPHINX_CONF <conf>]
      [RST_SOURCES <src>...]
      [MODULE_ONLY]
    )

  A set of documented CMake modules is scanned and converted into Sphinx input.
  The top-level directory of the generated documentation is the current binary
  directory of the calling project.

  ``BUILDTYPE``
    Set the requested Sphinx build type. If omitted, ``html`` is used.

  ``SPHINX_CONF``
    Template for the ``conf.py`` file passed to ``sphinx-build``. The final
    configuration file is generated with ``configure_file()``. If omitted, the
    default template shipped with dune-common is used.

  ``RST_SOURCES``
    Additional rst source templates configured into the build tree. If omitted,
    dune-common generates a default ``index.rst`` setup.

  ``MODULE_ONLY``
    Only document CMake functionality from the current Dune module.

  The documented CMake modules are expected to start with a bracketed ``.rst``
  documentation block. Public commands documented with ``.. cmake:command::``
  are collected into a flat public command reference, while commands marked
  with ``.. dune:internal::`` are excluded from that public command list.