Add contents.rst

Signed-off-by: Sung-Jae Lee <sj925.lee@samsung.com>

docs/contents.rst

@@ -0,0 +1,29 @@
+.. ONE documentation master file, created by
+   sphinx-quickstart on Thu May 14 18:13:12 2020.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Welcome to ONE's documentation!
+===============================
+
+.. toctree::
+   :maxdepth: 2
+   :caption: Contents:
+
+  ./overview/index
+  ./howto/index
+  ./runtime/index
+  ./compiler/index
+  ./common-ir/index
+  ./package/index
+  ./platform/index
+  ./device/index
+  ./test/index
+  ./release/index
+
+Indices and tables
+==================
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`