Update README.md

Added note to not run as root to avoid easy to miss errors during the fast-scrolling install that lead to WD permissions issues in node later during the testing phase.
Update README.md
Merge pull request #761 from Fmstrat/master

Update to README to avoid node errors
Explain what processes start up when running npm start
Merge pull request #767 from chilts/more-docs-on-processes

Explain what processes start up when running npm start