Of course, the wiki already does this: Tag:highway=path - OpenStreetMap Wiki
Additional tagging is highly recommended for paths. Without access and surface tags, routing engines may penalise the use of a path. Difficult hiking paths should be tagged with a sac_scale difficulty, to prevent people unwittingly choosing a route which is too difficult for them.
https://wiki.openstreetmap.org/wiki/Tag:highway%3Dtrack#How_to_map
Define the physical attributes of a track road with these supporting tags… adding these supporting tags is recommended if the information is available.