add CTT badge
.. image:: https://github.com/iotivity/iotivity-lite/actions/workflows/check-format.yml/badge.svg
:target: https://github.com/iotivity/iotivity-lite/actions/workflows/check-format.yml
+.. image:: https://github.com/iotivity/iotivity-lite/actions/workflows/ctt-test.yml/badge.svg
+ :target: https://github.com/iotivity/iotivity-lite/actions/workflows/ctt-test.yml
+
.. image:: https://img.shields.io/badge/works%20with-plgd%2Fcloud-success.svg
:target: https://github.com/plgd-dev/hub
