add dependabot config

Author: patinthehat

.github/dependabot.yml

@@ -0,0 +1,21 @@
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    labels:
+      - "github-actions"
+      - "dependencies"
+
+  - package-ecosystem: "composer"
+    directory: "/"
+    schedule:
+      interval: "daily"
+    allow:
+      - dependency-type: "direct"
+    versioning-strategy: increase-if-necessary
+    labels:
+      - "composer"
+      - "dependencies"