Fix JSDoc options @param for model classes

[colinrotherham]

Realised the JSDoc for model classes was in the wrong place so this PR moves them

It adds lots more red squiggles but they're finding lots of genuine things

E.g. Comparison of strings with booleans via === (but the JSDoc could be wrong)

[paulrobertlloyd]

Can’t keep a good man down… thanks for this @colinrotherham 😄

[colinrotherham]

No worries @paulrobertlloyd 😊

Kinda looks like you need both Thing (class) and ThingModel types, where:

• Dates are saved with string types in ThingModel as JSON data
• Dates are passed with string types in ThingModel for class options
• Dates are replaced with Date types in Thing as they become class instances

That way it's clear what you're working with at any given time