Clarify i18n upgrade process (#4334)
Clarify i18n upgrade process (#4334)

* Clarify i18n upgrade process

When importing the language files, the path has changed.

* Update upgrade-guide.md

fsgiudice/quasar,pdanpdan/quasar,quasarframework/quasar,quasarframework/quasar,rstoenescu/quasar-framework,pdanpdan/quasar,pdanpdan/quasar,fsgiudice/quasar,pdanpdan/quasar,quasarframework/quasar,quasarframework/quasar,rstoenescu/quasar-framework,fsgiudice/quasar,rstoenescu/quasar-framework