DRBD Config file is placed in wrong location

[Gr306]

On the DRBD documentation page at https://help.ubuntu.com/14.04/serverguide/drbd.html it says to copy the generated config file to /etc/drbd.conf

But installing the DRBD packages creates a generic drbd.conf file which has a line to include all *.res files in /etc/drbd.d

So the DRBD example should be trimmed slightly to be just a resource file (and not contain the global options) and instruct the user to copy it to the correct place.