Adding an index file to the documentation.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

docs/index.rst

diff --git a/docs/index.rst b/docs/index.rst
new file mode 100644
index 0000000..966f7b2
--- /dev/null
+++ b/docs/index.rst
@@ -0,0 +1,25 @@
+.. toctree::
+    :hidden:
+
+    versioning
+    naming
+
+    contributing
+    code-of-conduct
+
+Google maintained open source PDKs
+==================================
+
+This documentation includes information common to Google maintained open source PDKs.
+
+It should be included into the documentation shipped with those PDKs.
+
+.. include:: ../README.rst
+
+Resources
+=========
+
+The rendered documentation can be found at https://open-source-pdks.rtfd.io
+
+The source of the documentation can be found at https://github.com/google/opens-source-pdks
+