Create dependabot (#1373)

## Fixes Or Enhances
This PR adds a `dependabot.yml` configuration file to enable automated
dependency updates for:
- Golang
- GitHub Actions

**Make sure that you've checked the boxes below before you submit PR:**
- [ ] Tests exist or have been written that cover this particular
change.

@go-playground/validator-maintainers

.github/dependabot.yml

@@ -0,0 +1,12 @@
+version: 2
+updates:
+# Maintain dependencies for Golang
+- package-ecosystem: gomod
+  directory: "/"
+  schedule:
+    interval: weekly
+# Maintain dependencies for GitHub Actions
+- package-ecosystem: github-actions
+  directory: "/"
+  schedule:
+    interval: weekly