It looks great! I never really used Javadoc so please see this as a total outside feedback. I like the modern look, lighthouse is almost perfect in accessibility which is great (the only point lighthouse complains about it the contrast of links). It's also good on performance (80/100).

I have one confusion about the name, I'm used to the web frontend world where "ng" is usually something related to angular but it seems that it isn't the case here. I'm curious to know what's the origin of the name.