.ember-cli page does not document all options

Ported from: https://github.com/ember-cli/ember-cli/issues/9791

--------------------

https://cli.emberjs.com/release/appendix/configuration/

at the time of writing, it only lists:
```
"liveReload": false,
"disableAnalytics": false,
"port": 8080,
"proxy": "http://localhost:3000"
```

I _know_ there are at least 4 more options, but I forget what they're called :sweat_smile: