Add category for type:informational labels to release drafter (#1083)

Added a category for informational label, meaning we can set PR titles
such as in #1060 which will be
visible as the first thing in the release notes.

Signed-off-by: Elliot Gunton <elliotgunton@gmail.com>

.github/release-drafter.yml

@@ -2,6 +2,9 @@ template: $CHANGES
 name-template: v$RESOLVED_VERSION
 tag-template: $RESOLVED_VERSION
 categories:
+  - title: ℹ️ Information
+    labels:
+      - type:informational
   - title: ⭐️ Enhancements
     labels:
       - type:enhancement