Internationalization requirements for themes
If you want to submit a theme to be sold in the Shopify Theme Store, then your theme needs to be internationalized. An internationalized theme enables merchants to use the Shopify Language Editor to translate their storefront content into another language.
Optionally, your theme can include ready-made translations in one or more languages. For these languages, merchants won't have to create their own translations.
To meet Shopify's internationalization requirements for themes, include a locale file for each language that your theme supports and replace any hardcoded website content in your template files with translation keys.