Initial commit for the official OP-TEE documentation

This initial commit brings in all existing documentation found across
various gits making up the documentation for the OP-TEE project. So in
summary what this includes and what has been done is:

- Import all old documentation (optee_os, optee_client, optee_test and
  so on).
- Convert everything from markdown (*.md) to reStructuredText (*.rst).
- Add a couple of new pages (optee_docs, disclosure policy to name a
  few).
- Add Sphinx configuration.
- Add Travis configuration to enable automatic testing of future
  documentation patches.
- Finally, a general clean-up and verification of content,
  links as well as verification of build instructions etc has also been
  done.
diff --git a/index.rst b/index.rst
new file mode 100644
index 0000000..a1810f4
--- /dev/null
+++ b/index.rst
@@ -0,0 +1,28 @@
+OP-TEE Documentation
+####################
+This is the official location for OP-TEE documentation.
+
+.. toctree::
+   :maxdepth: 2
+
+   general/index
+
+.. toctree::
+   :maxdepth: 2
+
+   architecture/index
+
+.. toctree::
+   :maxdepth: 2
+
+   building/index
+
+.. toctree::
+   :maxdepth: 2
+
+   debug/index
+
+.. toctree::
+   :maxdepth: 2
+
+   faq/faq