Changes to ease installation

[alexives]

This pull request makes a few small changes that make it a little easier to install and run this (I hope!).

• Added a pm2 config file and instructions to let you manage it along with cncjs if you manage it with pm2.
• Updated the script to use the first user in the cncrc file if none is specified, that way you can start it without needing to dig through a file
• Removed CNCJS_SECRET note from the readme. It looks like this is already sourced from the cncrc file so I don't think this step is needed.