fix newDomParser

[timotheecour]

/cc @juancarlospaco my comment from #13920 (comment) was not addressed

this doesn't work, you must've pasted from a webpage and introduced an invisible symbol (see cat -e). you should make sure examples work
also, you should remove outer parens

before PR, newDomParser will not work, giving Uncaught SyntaxError: Unexpected identifier in a browser
this won't show up in github UI, you can only see the difference locally using cat -e

CI failure unrelated and would be fixed by #13984

[Varriount]

Is there a way to test this?

[timotheecour]

in my unreleased patch, i can do smthg like nim js -d:nimbrowser main and it opens in browser a template html that links against generated js; but you can do the same manually