feat: introduce dependabot

.github/dependabot.yml

@@ -0,0 +1,23 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+updates:
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+      day: "thursday"
+      time: "07:00"
+      timezone: "Asia/Tokyo"
+    reviewers:
+      - sawadashota
+      - kensei18
+      - ryosan-470
+    groups:
+      patch-minor:
+        update-types:
+          - "patch"
+          - "minor"