demo data install script (ci skip)

Just added a bash script that can be called to install demo data. I intend to reference this in the installation guide.
The cat is unnecessary and the grep is unused, so it could be just:
/opt/axsh/wakame-vdc/dcmgr/bin/vdc-manage -e <<CMDSET

Also, if vdc-manage can handle leading whitespace, indenting would
make it easier to read.