Create dependabot.yml (#134)

* Create dependabot.yml

* Update dependabot.yml

* Integrate proposals from Soule

.github/dependabot.yml

@@ -0,0 +1,21 @@
+version: 2
+
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    groups:
+      # xref: https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#groups
+      ci:
+        patterns:
+          - "*"
+    schedule:
+      interval: "weekly"
+      day: "sunday"
+  - package-ecosystem: "gomod"
+    directory: "/"
+    groups:
+      go:
+        update-types:  ["minor","patch"]
+    schedule:
+      interval: "weekly"
+      day: "sunday"