ci: migrate dependabot config file to v2

.github/dependabot.yml

@@ -0,0 +1,14 @@
+version: 2
+updates:
+  - package-ecosystem: npm
+    directory: '/'
+    schedule:
+      interval: daily
+      time: '08:00'
+      timezone: Japan
+    labels:
+      - 'dependabot:robot:'
+    commit-message:
+      prefix: fix
+      prefix-development: chore
+      include: scope

README.md

@@ -4,7 +4,6 @@
 [![Node CI Status](https://github.com/ddradar/consumer-ddr/workflows/Node%20CI/badge.svg "Node CI Status")](https://github.com/ddradar/consumer-ddr/actions?query=workflow%3A%22Node+CI%22)
 [![codecov](https://codecov.io/gh/ddradar/consumer-ddr/branch/master/graph/badge.svg)](https://codecov.io/gh/ddradar/consumer-ddr)
 [![CodeFactor](https://www.codefactor.io/repository/github/ddradar/consumer-ddr/badge)](https://www.codefactor.io/repository/github/ddradar/consumer-ddr)
-[![Dependabot Status](https://api.dependabot.com/badges/status?host=github&repo=ddradar/consumer-ddr)](https://dependabot.com)
 [![License](https://img.shields.io/github/license/ddradar/consumer-ddr)](LICENSE)
 
 Consumer DDR Song List