Mark required fields

[nlhkabu]

Closes #6281

[di]

I think it might be better to add something like:

{% if field.flags.required %}(Required){% endif %}

to every field, so this happens automatically instead of having to be done manually.

Might make sense to use a macro to render a field in a consistent way so we only have to do this in one place, but that would also require figuring out where to set the human-readable field name, and doing it for all the fields.

[nlhkabu]

Hi @di, @woodruffw - I've updated this PR to use field.flags.required as suggested, and opened a ticket for creating a field macro here: #6393