Merge pull request #420 from squat/re-enable_dependabot_for_yarn

fix(security): enable Dependabot for Yarn

.github/dependabot.yml

@@ -17,3 +17,7 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
+  - package-ecosystem: "npm"
+    directory: "/"
+    schedule:
+      interval: "weekly"