add support for embed blocks, with some styling for youtube

dnscms/dnscms/blocks.py

@@ -6,6 +6,7 @@ from grapple.models import (
     GraphQLString,
 )
 from wagtail import blocks
+from wagtail.embeds.blocks import EmbedBlock
 from wagtail.images.blocks import ImageChooserBlock
 
 BACKGROUND_COLOR_CHOICES = (
@@ -240,6 +241,7 @@ BASE_BLOCKS = [
     ("page_section_navigation", PageSectionNavigationBlock()),
     ("accordion", AccordionBlock()),
     ("fact_box", FactBoxBlock()),
+    ("embed", EmbedBlock()),
 ]