Understandable that you're adding support for languages and packaging ecosystems as you go, and JS + PHP is as good a place as any to start, but it would be helpful if this were explicitly highlighted. For those who are unfamiliar with the ecosystems in question, package.json and composer.json are just filenames that don't actually tell you anything.
It would be helpful, and the site creator should list it. However, let's not treat this as a fault. They're offering you a free service and can't launch with every issue already resolved before being identified.
Re-reading my comment I can see it reads a bit like that - I totally don't intend any notion that I expect everything to be perfect, I'm an open source developer myself and as you say we don't expect every issue to be resolved instantly!