Documentation improvement

[ppintosilva]

• Better TL;DR section: include bullet point about writing the orchestra+instruments input files
• Add to troubleshooting section:
  • Exceeding quotas - example
  • Warnings - supplementary roles
  • Don't forget to rerun maestro every time you change orchestra/instruments
• Use Wiki instead - otherwise the documentation is too long?
• Add url to my-cluster-with-maestro gist
• Best Practices:
  • start with dummy role for all in instruments - verify that it works and then try your own roles
  • don't be afraid to re-run playbooks - they are idempotent
  • design your roles to be idempotent