Add instruction to put strings into quotes

[Darkona]

https://github.com/Tiviacz1337/Travelers-Backpack/blob/ba2a5206e3eddb5ed4c7557a301709dcae516eff/src/main/java/com/tiviacz/travelersbackpack/config/TravelersBackpackConfig.java#L182C26-L182C33

Instructions for list of items should indicate the names need to be between quotes, because the underlying parser (https://github.com/TheElectronWill/night-config/blob/master/toml/src/main/java/com/electronwill/nightconfig/toml/ValueParser.java) will look for them for strings.