@use array format validation

Within v2, when a format that's passed is not passed as a multidimensional array, either validate the array and fire back a warning/error, or transform the array to a multidimensional array with a "*"

e.g. 
`injectGlobalPaths: ["some-path/global.scss"]` 

Either errors or transforms into: `injectGlobalPaths: [["some-path/global.scss", "*"]]` 