Some words are in the source code of the theme, but are not available for translation in the .pot file.
So if I add these words in the /themes/jevelin/languages/jevelin.pot file I’ll be able to translate. But I’m not sure that in future thema updates, those words will remain.
What is the correct way to add new words and not miss out on a future update?
I hope you are well today and thank you for your question.
We will update the POT file in the future version of theme.
You can update it easily using poedit as described in this page http://help.wprentals.org/article/how-to-update-the-po-translation-after-a-theme-update/ or use Loco Translate plugin as described here https://support.shufflehound.com/theme-translation/