doc: specify that xelatex is used as Latex engine
Building the pdf documentation on readthedocs.org fails with pdflatex.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/doc/conf.py b/doc/conf.py
index 8bb27ad..93250a6 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -31,6 +31,8 @@
# If your documentation needs a minimal Sphinx version, state it here.
needs_sphinx = '1.3'
+latex_engine = 'xelatex'
+
# Add any Sphinx extension module names here, as strings. They can be
# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
# ones.