Great job! Would be lovely to have filters on when language was created. Also one minor nit, I am not super mouse oriented person and wanted to bookmark the site but ctrl+d is mapped to scroll down.

Thanks for raising that. I've changed that key mapping now to a less common one to avoid conflicts.

I am not very familiar with Python. How do you localize (translate) first one?

You don't with f-strings because they're substituted eagerly. You could with the new t-strings proposed here because you can get at the individual parts.

That's what t-strings are about. They are lazy, so you can mark them for translation "as-is".