Explain basic plan in the README

[drphilmarshall]

Include:

• Note about starting this at 2018 sprint week
• Semi-disposable code
• Building off Sean's CMU Hack Day project
• Limitations:
  • Will only work at NERSC
  • Targeted at DC2 Run 1.1p Truth table and Object table
  • "Simple" machine learning training, to map N truth properties to M observed properties, and ignoring blended objects.
• Contact details, Slack channel, etc.