ci: enable dependabot (#87)

Co-authored-by: Vojtech Simetka <vojtech@simetka.cz>

Author: AuHau

.github/dependabot.yml

@@ -0,0 +1,8 @@
+version: 2
+updates:
+  - package-ecosystem: "npm"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    # Always increase the version in package.json as well (for patch versions by default only package-lock.json is updated)
+    versioning-strategy: increase