add support for previewing pages

dnscms/contacts/models.py

@@ -11,6 +11,7 @@ from wagtail.fields import RichTextField, StreamField
 from wagtail.models import Page
 from wagtail.search import index
 from wagtail.snippets.models import register_snippet
+from wagtail_headless_preview.models import HeadlessMixin
 
 from contacts.blocks import ContactSectionBlock
 from dnscms.blocks import BASE_BLOCKS
@@ -22,7 +23,7 @@ PHONE_REGEX_VALIDATOR = RegexValidator(
 
 
 @register_singular_query_field("contactIndex")
-class ContactIndex(Page):
+class ContactIndex(HeadlessMixin, Page):
     max_count = 1
     subpage_types = []