User openmw-cs.cfg has comment talking about settings.cfg

https://gitlab.com/OpenMW/openmw/-/blob/master/components/settings/parser.cpp#L255-260 helpfully adds a comment to the user settings.cfg and openmw-cs.cfg, but in both cases, what it says is only correct for settings.cfg. This should be changed to talk about the correct pair of files. One of them should be really easy on account of just being the filename passed to the function.