Netlify cms Multiple relation widget

This widget is meant to help does who want to select through more then one collation at Relation widget of netlify cms

How to use:

1. In script on your page you have to add this code:
<script>
    CMS.registerWidget('multiple-relation', MultipleRelationControl, MultipleRelationPreview)
</script>

2. Use it in config.yml

- label: 'Sections'
  name: 'section'
  widget: 'multiple-relation'
  options:
    - { label: "Section title", value: "collations" }
  searchFields: ['title']
  displayFields: ['title']
  valueField: 'title'

If you want to add an extra option to the relation you can add it like this

- label: 'Sections'
  name: 'section'
  widget: 'multiple-relation'
  options:
    - { label: "Section title", value: "collations" }
    - label: "Section 1 title"
      value: "collations1"
      extraOptionName: 'extraOptionName'
      extraOptions:
        - { label: "Value1", value: "value" }
        - { label: "Value2", value: "value2" }
  searchFields: ['title']
  displayFields: ['title']
  valueField: 'title'