Incorrect typings for FieldArray.initialValues

### Are you submitting a **bug report** or a **feature request**?

Bug report

### What is the current behavior?

I got an error when pass initialValues as an array

```
interface MyType {
name: string;
}
...

name="test" initialValue={[{name: ''}]}>

```

Error:
Type: MyType[] has no properties in common with type MyType;

### What is the expected behavior?

Compiling without errors

### Sandbox Link

### What's your environment?
"final-form": "^4.18.2",
"final-form-arrays": "^1.1.2",
"react-final-form": "^6.3.0",
"react-final-form-arrays": "^3.1.1",

### Other information

I assume it can be solved by changing
```
export interface UseFieldArrayConfig
extends UseFieldConfig {
isEqual?: (a: any[], b: any[]) => boolean
}
```
to
```
export interface UseFieldArrayConfig
extends UseFieldConfig {
isEqual?: (a: any[], b: any[]) => boolean
}
```