Add initial API doc configuration

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/docs/index.rst b/docs/index.rst
new file mode 100644
index 0000000..33a9722
--- /dev/null
+++ b/docs/index.rst
@@ -0,0 +1,20 @@
+.. Mbed TLS Versioned documentation master file, created by
+   sphinx-quickstart on Thu Feb 23 18:13:44 2023.
+   You can adapt this file completely to your liking, but it should at least
+   contain the root `toctree` directive.
+
+Mbed TLS API documentation
+==========================
+
+.. doxygenpage:: index
+   :project: mbedtls-versioned
+
+.. toctree::
+   :caption: Contents
+   :maxdepth: 1
+
+   Home <self>
+   api/grouplist.rst
+   api/filelist.rst
+   api/structlist.rst
+   api/unionlist.rst