Incorrect example for background-image in example config.yml file

[JamieMcH]

Describe the bug
Example config.yml file has an incorrect string for background-image: that doesn't work for actually pointing to a local file.

Configuration
The correct string should be:

background-image: "/assets/your/light/bg.png"

Current example misses the leading '/'

[DarkenLight]

I spent 30 minutes diagnosing the issue and was checking the browser console for errors. I initially thought there was a problem with the code because requests were being made to <ip_address>/resources instead of <ip_address>/assets. Thank you for pointing out the missing leading slash in the main example— I would have spent much more time troubleshooting otherwise.