Localisation of Casper


New here, and Im am looking to translate Casper to Swedish.
I have a handlebars json file for the localisation, but I am not sure how to proceed.

If I understand https://ghost.org/docs/api/v3/handlebars-themes/helpers/translate/ correctly, all i have to do is create a folder named /locales and put the sv.json file in it?

Or is Casper a theme that does not support adding new locales to it without custom code as well?