Dependencies are present to provide infra support, namely linting. To install, run yarn, then to lint, run yarn lint. Easy peasy.

If you're trying to test the auto-reload locally, you'll have to run through a server using e.g. one of:

$ ruby -run -ehttpd . -p8000
$ python2 -m SimpleHTTPServer
$ python3 -m http.server 8000

...and head to http:https://localhost:8000/.

main.js is the file with the list of things to display and probably what you want to edit.