v4.2.0
Adds a new feature, requested by @ampproject/wg-infra. You can now move configuration for filesize outside of your package.json if you desire.
Passing an argument of -c=${path/filesize.json} with a valid json object using the same structure as the package.json variant will use this configuration instead of package.json as the source of truth.
The file name is not required to be filesize, but the passed configuration file must be valid json and end in a .json extension.