docs: index.rst is expected at the project root

conf.py

@@ -69,7 +69,7 @@
 
 
 # The master toctree document.
-master_doc = 'docs/index'
+master_doc = 'index'
 
 
 # man_pages = [ master_doc, ("docs/BUILD", "build", "building", "authors", "sectionbuild") ]

index.rst

@@ -0,0 +1,62 @@
+.. Spirit documentation master file, created by
+    sphinx-quickstart on Thu Jul 13 16:49:07 2017.
+    You can adapt this file completely to your liking, but it should at least
+    contain the root `toctree` directive.
+    :navtree_shift: True
+    :navtree_root_links: True
+
+Spirit - Spin Simulation Framework
+==================================
+
+.. image:: https://imgur.com/iWc1kuE.png
+
+.. toctree::
+    :maxdepth: 1
+
+    Introduction                 <README>
+    Qt desktop user interface    <docs/UI-Qt>
+    ImGui desktop user interface <docs/UI-ImGui>
+    Input file specification     <core/docs/Input>
+    Definitions                  <core/docs/Definitions>
+    Additional features          <core/docs/Features>
+    Hamiltonian                  <core/docs/Hamiltonian>
+
+.. toctree::
+    :maxdepth: 2
+    :caption: Installation
+
+    Build on Unix/OSX   <docs/Build_Unix_OSX>
+    Build on Windows    <docs/Build_Windows>
+    Using Docker        <docs/Docker>
+
+.. toctree::
+    :maxdepth: 3
+    :caption: C API
+
+    Usage           <core/docs/C_API>
+    Full Reference  <core/docs/c-api/API_Reference>
+
+.. toctree::
+    :maxdepth: 3
+    :caption: Python API
+
+    Usage           <core/docs/Python_API>
+    Full Reference  <core/docs/python-api/API_Reference>
+
+.. toctree::
+    :maxdepth: 1
+    :caption: Further Information
+
+    License                 <https://github.com/spirit-code/spirit/blob/master/LICENSE.txt>
+    Contributing            <docs/CONTRIBUTING>
+    Contributors            <docs/CONTRIBUTORS>
+    Referencing this Code   <docs/REFERENCE>
+    Included dependencies   <docs/Dependencies>
+
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`