Linguistic Focus should have an option to use single quotes

Currently, the Linguistic Focus works exclusively using double quotes. Since double quotes are not the standard in foreign languages, like Dutch, an option to select using single quotes should be available.

A this time in version, this function is unusable for publication quality fiction in languages that use single quotes for Direct Speech.

It uses the Single/Double Quotes that you have specified in the Scrivener options. Adjust them to Dutch and it should work as expected.