docs(troubleshooting): added instructions on manually updating CoreOS
ref(troubleshooting): move coreos upgrade docs
style(docs): style cleanup
docs(upgrading): mention CoreOS minimum requirement
fix(builder): force newline
ref(deisctl): purge update engine logic
Merge pull request #2404 from bacongobbler/force-newline

fix(builder): force newline
Merge pull request #2397 from bacongobbler/patch-7

docs(troubleshooting): added instructions on manually updating CoreOS
Merge pull request #2419 from gabrtv/remove-updater

ref(deisctl): purge update engine logic