GeoJSON specification RFC 7946 conformity

Nobody has claimed this yet.

Per updated GeoJSON spec: https://datatracker.ietf.org/doc/html/rfc7946#section-3.1.6

Polygon specification now indicates:
```
A linear ring MUST follow the right-hand rule with respect to the
area it bounds, i.e., exterior rings are counterclockwise, and
holes are clockwise.
```

Problem:
`mercantile` utilizes clockwise pattern which is the inverse of specified counter-clockwise pattern for polygon feature creation.

Impacted LoC: https://github.com/mapbox/mercantile/blob/fe3762d14001ca400caf7462f59433b906fc25bd/mercantile/__init__.py#L835

Short term workaround for my use case:
```
def as_geom(qk: str):
t = mercantile.quadkey_to_tile(qk)
west, south, east, north = mercantile.bounds(t)
return {
"type": "Polygon",
"coordinates": [[
[east, north],
[west, north],
[west, south],
[east, south],
[east, north],
]],
}
```

Start with mercantile/__init__.py at line 835 and compare the polygon coordinate order with RFC 7946 section 3.1.6. Check the existing test suite for polygon or geometry expectations. Done means polygon features created by mercantile use the RFC-specified exterior-ring winding without breaking existing tile-boundary behavior.

Written by the indexing model from the issue text.