Docs: Working with Forms (validation, submitting, different states, etc)

[peterpme]

A common question among beginners: how do I use forms? Can I use Formik? etc

• Start with the basics (how far can we get with just vanilla reason)
• Introduce a form library (whether thats re-formality, or a javsacript one like Formik)
• Common javascript use cases and how they convert to Reason
• debouncing? does that fall into this?