add figure margin in articles and image block blueprint

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

assets/css/src/article.css

@@ -46,6 +46,10 @@ article ol {
   margin-left: var(--unit--horizontal);
 }
 
+article figure {
+  margin: 4rem 0;
+}
+
 article figure img {
   max-width: 100%;
 }

site/blueprints/blocks/image.yml

@@ -0,0 +1,27 @@
+name: field.blocks.image.name
+icon: image
+preview: image
+fields:
+  image:
+    label: field.blocks.image.name
+    type: files
+    query: model.images
+    multiple: false
+    image:
+      back: black
+    uploads:
+      template: blocks/image
+  alt:
+    label: field.blocks.image.alt
+    type: text
+    icon: title
+    help: Lu par les robots d'indexation, par les lecteurs d'écran et affiché à la place de l'image si celle-ci ne charge pas.
+  caption:
+    label: field.blocks.image.caption
+    type: writer
+    icon: text
+    inline: true
+  link:
+    label: field.blocks.image.link
+    type: text
+    icon: url