chore(dependabot): add npm and groupings

Author: duncdrum

.github/dependabot.yml

@@ -5,4 +5,23 @@ updates:
   schedule:
     interval: "weekly"
   commit-message:
-    prefix: "chore(gha):"
+    prefix: "chore(gha):"
+  groups:
+    github-actions:
+      patterns:
+        - "*"
+- package-ecosystem: "npm"
+  directory: "/"
+  schedule:
+    interval: "weekly"
+  commit-message:
+    prefix: "chore(deps):"
+  groups:
+    commitlint-dependencies:
+      patterns:
+        - "@commitlint/*"
+    semantic-release-dependencies:
+      patterns:
+        - "@semantic-release/*"
+        - "semantic-release"
+        - "conventional-changelog-*"