Looking at the source, it seems to be part of the title. Chrome (and Chromium based browsers don't appear to display it. It was probably just a bad copy paste.

Looking at the source, it seems to be part of the title. Chrome (and Chromium based browsers don't appear to display it. It was probably just a bad copy paste. I have seen invisible characters used intentionally as markers or invisible water marks but I doubt that's happening here.