PrimaryCursor to also be an array?

[arfath-linklet]

In cases where the deterministic primary column is not a single column but a compound/composite key, we'd need a 'primaryCursor' array.

Currently experimenting with adding the first half of composite key to be in the 'cursors' array instead like so:

cursors: [
    { order: "ASC", key: 'createdAt', schema: Table.createdAt },
    { order: "ASC", key: "composite1", schema: Table.composite1 }
],
primaryCursor: { order: "ASC", key: "composite2", schema: Table.composite2 }