When using `@bbob/react`s `<BBCode>` component, the following error is thrown
if this change is not included...
```
Warning: Each child in a list should have a unique "key" prop.
```
Mentioned in #28
You need to pass a valid prop checking function to `PropTypes.arrayOf`. This caused
an error to be thrown in development for me:
```
Warning: Failed prop type: Unexpected token function
```
Greg Venech