upgrade path for amenity=youth_centre

[westnordost]

As promised in #83, here is a follow-up for the upgrade path of deprecated amenity=youth_centre -> amenity=community_centre + community_centre=youth_centre. It looks like another upgrade path was already added in the meantime, but it is not quite correct or at least not consistent with the tagging in #83:

community_centre:for specifies actually rather a property of a community centre/youth centre, while community_centre specifies the type of community centre, i.e. is part of what it defines as a map feature. See PR #83

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I don't know, hypothetical example: There could be a general community centre for bingo-playing and a community centre dedicated to hands-on creating art and music each in a residential complex for old people. Both are for old people, but there are different kinds of community centres. The "for" does not define the type of community centre necessarily and that is why both community_centre key exist and community_centre:for key exist.

[tyrasd]

It looks like another upgrade path was already added in the meantime

Actually, it was already added a while ago in openstreetmap/iD@aca699e. It would indicate that these upgrade paths were copied over from osmose. Not sure if these rules are still in there somewhere, but at first glance I can't find them over at the osmose repository.

Anyway thanks for the PR (even though there are now almost no amenity=youth_centre remaining)!