Update ILC README & config file

[bbartling]

Update configuration store directions:

1. For example I have been using the web app developed config file (in my case its ilc_config.json) and copying it to $ cp ilc_config.json ~/.volttron/configuration_store/ilc.agent.store to install the config file as well as having to restart VOLTTRON.
2. Also update directions on how install the agent per correct config store/file implementation.
3. What would be the long term solution when someone would want to modify the ILC agent config file without having to restart VOLTTRON with the methods described above? From what I have tried I cannot modify the ILC config file when its running LIVE. For example if I wanted to adjust the demad_limit setpoint I cannot edit it....I have to redo the config file with the steps described above & restart VOLTTRON

[bbartling]

@rlutes or @craig8 can you remember the fix we made earlier this summer to get the ILC agent up and running in our 8.0 platform? Was there a git issue created for that? Or was the fix implemented into VOLTTRON version 8.2? Now that we updated our edge device to test the open ADR new 8.2 open ADR agent I think this fix maybe lost. At least with my botched update attempt...

I think it was somewhere in services.core some Python file deep inside VOLTTRON where with the help of Robert I added in an IF/ELSE statement.

I can post the fix here once its figured again if there is no paper trail.