app/views/challenges/form/_submission_file_definition_fields.html.erb
<div class="section-container nested-fields">
<a class="ss-icon" href="#"></a>
<%= f.label :submission_file_description, 'Submission file description' %>
<%= f.text_field :submission_file_description %>
<%= f.label :filetype %>
<%= f.select :filetype,
enum_option_pairs(SubmissionFileDefinition, :filetype),
include_blank: false %>
<%= f.check_box :file_required, {}, "true", "false" %>
<label>File required</label>
<%= link_to_remove_association "remove", f, class: 'pull-right' %>
</div>