Updated form quickstart to show example of using array config for validators

Two comments:

- 50 for a max length on a name field seems both arbitrary and potentially restrictive. :)
- Setting the "break chain on failure" flag here makes no sense, as it only affects the current validation chain, not the set of inputs. Since no other validators are present, it will have no effect. As such, during merge, I'm going to remove this line. Developers can find it in the ValidatorChain and/or InputFilter documentation.