Merge pull request RasaHQ#4945 from RasaHQ/fix-wrong-endpoint-linkdoc-link

fix wrong link to endpoint

Author: tmbo

docs/core/actions.rst

@@ -184,7 +184,7 @@ for example to display the output of a long running background operation
 or notify the user of an external event.
 
 To do so, you can ``POST`` to this
-`endpoint <../../api/http-api.html/#operation/executeConversationAction>`_ ,
+`endpoint <../../api/http-api/#operation/executeConversationAction>`_ ,
 specifying the action which should be run for a specific user in the request body. Use the
 ``output_channel`` query parameter to specify which output
 channel should be used to communicate the assistant's responses back to the user.