fix: nested JSON files not being added correctly

[garyforsterio]

When using a JSON structure with nested keys, e.g.

{
  "rootKey": "Value",
  "category" : {
    "nestedKey": "This doesn't work currently"
  }
}

the current code is using addResources which seems to support on key/value pairs (docs here. By changing this to addResourceBundle it is possible to add support for key/value pairs using this plugin