I think you’d need to make your request here: Issues · openstreetmap/openstreetmap-website · GitHub This is the repository for the website code, making links to e.g. Wikipedia clickable.
As an alternative, there’s already browser extension that turns Wikidata IDs into links - just for people who have the extension installed. If you have some coding experience, then modifying this extension to work for GNIS IDs might be a more “lightweight” option if you just want it for yourself, instead of every user of the OSM website.