Aliases for "nudist" tag

The bulk update request #14918 has been approved by @evazion.

create alias naturism -> nudist
create alias nudism -> nudist

Well, the tag nudist is basically used for naturism posts (as the wiki page even linked to Wikipedia page for naturism), so I think it should be aliased as such.

The bulk update request #14918 (forum #232355) has been approved by @evazion.