Add Twitter and Readthedocs shields (#298) (#299)

* Add Twitter and Readthedocs shields

Signed-off-by: Pablo Garrido <pablogs9@gmail.com>

* Fix

Signed-off-by: Pablo Garrido <pablogs9@gmail.com>
(cherry picked from commit f47b29e)

Co-authored-by: Pablo Garrido <pablogs9@gmail.com>

README.md

@@ -5,6 +5,8 @@
 [![Issues](https://img.shields.io/github/issues/eProsima/Micro-XRCE-DDS-Agent.svg)](https://github.com/eProsima/Micro-XRCE-DDS-Agent/issues)
 [![Forks](https://img.shields.io/github/forks/eProsima/Micro-XRCE-DDS-Agent.svg)](https://github.com/eProsima/Micro-XRCE-DDS-Agent/network/members)
 [![Stars](https://img.shields.io/github/stars/eProsima/Micro-XRCE-DDS-Agent.svg)](https://github.com/eProsima/Micro-XRCE-DDS-Agent/stargazers)
+[![Read the Docs](https://img.shields.io/readthedocs/micro-xrce-dds?style=flat)](https://micro-xrce-dds.docs.eprosima.com/en/latest/)
+[![Twitter Follow](https://img.shields.io/twitter/follow/eprosima?style=social)](https://twitter.com/EProsima)
 
 [![Docker Build Status](https://img.shields.io/docker/cloud/build/eprosima/micro-xrce-dds-agent)](https://hub.docker.com/r/eprosima/micro-xrce-dds-agent/)