Feature Request: Option to promote a geojson feature property to top level ID

[samgehret]

With the introduction of setFeatureState into GL-JS, it is increasingly important to have control over the top level ID of features within a vector tile.

Take the following example: I download a shape file from the census website, convert it to geojson, run through tippecanoe, and upload to mapbox as a vector tile. Now I want to use setFeatureState to style the polygons in the vector tile. But I cannot, because the top level IDs of the polygon features are generated sequentially/randomly.

It would be great, if running my geojson through tippecanoe, if I could choose which of the geojson properties would be promoted to the top level ID of each feature.

cc @ericfischer

[e-n-f]

OK, I can add a --use-attribute-for-id option that will treat a specified feature attribute as if it were the id field.

[e-n-f]

OK, this will also be in #658.

[e-n-f]

Merged