ArrayField `initialValue` prop type is not correct

[SamSamskies]

Describe the bug
TypeScript complains when trying to set initialValue to an array with more than 1 item when you should be able to initialize it with more than 1 item. I think the type should be unknown[] and not [unknown].

informed/index.d.ts

Line 451 in 5537b51

initialValue?: [unknown];

To Reproduce

Initialize ArrayField component with an array like in the example provided in the docs.

https://teslamotors.github.io/informed/getting-started/array-field