Add GitHub Actions package ecosystem to Dependabot

Added support for GitHub Actions in Dependabot configuration.

Author: codeafix

.github/dependabot.yml

@@ -15,3 +15,9 @@ updates:
     schedule:
       interval: "weekly"
     target-branch: "develop"
+  - package-ecosystem: "github-actions"
+    # Workflow files stored in the default location of `.github/workflows`
+    # You don't need to specify `/.github/workflows` for `directory`. You can use `directory: "/"`.
+    directory: "/"
+    schedule:
+      interval: "weekly"