Adding dependabot config

Taking care for new(er) docker images and github actions

For more information see:
https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuring-dependabot-version-updates

.github/dependabot.yml

@@ -0,0 +1,19 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: daily
+      time: "04:00"
+    pull-request-branch-name:
+      separator: "-"
+    open-pull-requests-limit: 10
+  - package-ecosystem: docker
+    directory: "/"
+    schedule:
+      interval: daily
+      time: "04:00"
+    target-branch: "master"
+    pull-request-branch-name:
+      separator: "-"
+    open-pull-requests-limit: 10