Add a note about Node.js version requirement (#371)
Add a note about Node.js version requirement (#371)

* Add a note about Node.js version requirement

* Update quasar-upgrade-guide.md

rstoenescu/quasar-site,quasarframework/quasar-framework.org,rstoenescu/quasar-site,quasarframework/quasar-framework.org,rstoenescu/quasar-site,quasarframework/quasar-framework.org