Update README.md

Now, with the virtualenv activated, navigate to the EnergyPlus-PBC directory.

You must alter the config.json file to hold the locations pointing towards your:

    1) volttron home directory

    2) the maximum number of zones that you would like to limit the PBC control

    2) energyplus_config directory

    3) energyplusagent directory

    4) controlagent directory

    5) the maximum number of zones that you would like to limit the PBC control

       to

    The paths must be absolute paths

The suggested max number for peak shaving is half the available loads.

Allowing all the zones to run will correspond to uncoordinated control.