Does the example regular expression in README still work?

I have added the following block of code to my `~/.vimrc` from the README:

```vim
function! s:SetupGhostBuffer()
    if match(expand("%:a"), '\v/ghost-(github|reddit)\.com-')
        set ft=markdown
    endif
endfunction
```

I see the file type is set to markdown even on https://microsoft.github.io/monaco-editor/, but I cannot figure out why.

Can you please help with this issue?