Inaccurate result for union examples

[brandonmcconnell]

Both in the main README and in the comment within the linked source, the result is presented as [1, 2, 3, 4, 5, 6], but the actual result is [1, 2, 5, 6, 3, 4], since arrays intrinsically respect insertion order.

I found this confusing as it seemed to suggest that union also employed sorting of its own, when in fact it does not, but was rather a misforecasted result.

TL;DR

Re union (in README | linked source), [1, 2, 3, 4, 5, 6] ≠ [1, 2, 5, 6, 3, 4]

[brandonmcconnell]

This issue will be fixed by merging PR #503