Aha! Finally, took quite a while from RC6.
Quick test result: Still no rtl.js found, but it's mentioned in README.md. This is getting very close to newbie friendly distribution, just missing top level README.md to configure PATH to find the compiler or maybe update README.md in demo to use relative path when calling the compiler and referring to rtl.js with -Ji, otherwise it's still look too magical to be able to do:
$ pas2js -Jc -Jirtl.js somedemo.pas
from demo folder. One great point that the .cfg is useable right out of the box.