Today I tried implementing an extra file for supporting different translations. It worked in my tests. I added Greek and English translations. I got stuck in the refresh event when I change language. I think I found what the problem is and in 1-2 days I hope the new version will be ready.

How it works: First I replaced all text in my main file with placeholders. Then,I made a JS script that replaces placeholders with the correct language. The process is done with the onload.