Add Dependabot configuration file

The .github/dependabot.yml configuration file was added to automatically check for updates on github-actions and docker packages weekly. This is expected to ensure that the project is always running on the latest, most secure versions of these packages.

.github/dependabot.yml

@@ -0,0 +1,17 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "monday"
+      time: "00:00"
+    groups:
+      all-actions:
+        patterns: [ "*" ]
+
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "monday"