New Extension: Divider (#1050)

* Link to divider’s extension

* Fix whitespaces

* Divide image size by 2

docs/extensions.html

@@ -3,6 +3,11 @@ title: Extensions
 layout: default
 route: extensions
 extensions:
+- name: bulma-divider
+  url: https://github.com/Wikiki/bulma-divider
+  slug: bulma-divider
+  width: 1112
+  height: 676
 - name: bulma-calendar
   url: https://github.com/Wikiki/bulma-calendar
   slug: bulma-calendar