Update getting_started.rst with new causal discovery info

Announce the availability of causal discovery online.

Signed-off-by: Yujia Zheng <yjzheng19@gmail.com>

Author: kunwuz

docs/source/getting_started.rst

@@ -5,7 +5,7 @@ Getting started
 
 
 News
-------------
+^^^^^^^^^^^^
 
 Causal discovery is now available **anytime**, **anywhere**!