Arabic/Persian are not supported in demo

I'm asking since it is advertised in the README that they are supported.

As you can see, the text `سلام دنیا‍` in my native terminal is rendered as `دنیا سلام` and `سلام` is in the error message, but in the ghostty demo it becomes `م‌ا‌ل‌س` (characters are reversed and separated). This is my biggest problem with xterm.js as well, it would be great if ghostty address it.