Template is editable at Template:Generic:Map Features:tourism - OpenStreetMap Wiki - and I added comment into page code to help with this.
But I would create first https://wiki.openstreetmap.org/wiki/Tag:tourism%3Dholiday_village - such rarely used tags should be first document at their own page, with listing at main overview pages as something optional
Creating a page describing key or value - OpenStreetMap Wiki may help in this