[Tagging] Deprecation proposal: man_made=drinking_fountain

[Davidoskky]

> everybody can write everything in the wiki, but man_made=drinking_fountain is a low usage tag and drinking_fountain=yes is virtually unused (10 times globally), whoever wrote this didn’t research actual usage. Where is it written?

It is written here: 
https://wiki.openstreetmap.org/wiki/Tag:man_made%3Ddrinking_fountain I 
did not want to delete the line myself, but I feel it would be sensible.