Migrated the rest of the narrative documentation from Latex to Sphinx
diff --git a/doc/index.rst b/doc/index.rst
index c083d3d..b9c80cf 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -18,6 +18,7 @@
    introduction
    install
    api
+   internals
 
 Indices and tables
 ==================