[EAP 7.1 Beta Release Notes] Notify customer that there are currently issues with the example files for EC2

Assuming JBEAP-12124 won't be fixed in Beta documentation, we should notify customers that the paths to which we're referencing in docs are not good.

For standalone, the correct example path is: /opt/rh/eap7/root/usr/share/wildfly/docs/examples/configs/standalone-ec2-ha.xml.

For domain, there is currently no correct example file (JBEAP-12047), but the changes necessary for creating one are relatively simple and customers can see them in the standalone EC2 example configuration file.