chore(ci): Add and configure Dependabot (pyOpenSci#79)

* Dependabot config file for the repository

* Dependabot config file for the template

* Apply suggestion from @lwasser

* Apply suggestion from @lwasser

---------

Co-authored-by: Leah Wasser <leah@pyopensci.org>

Author: agriyakhetarpal

.github/dependabot.yml

@@ -0,0 +1,16 @@
+version: 2
+updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directories:
+      - "/"
+      - "template/{% if use_git and dev_platform == 'GitHub' %}.github{% endif %}/workflows"
+    schedule:
+      interval: "monthly"
+    commit-message:
+      prefix: "dependencies: "
+      include: scope
+    groups:
+      actions:
+        patterns:
+          - "*"

template/{% if use_git and dev_platform == 'GitHub' %}.github{% endif %}/dependabot.yml

@@ -0,0 +1,15 @@
+version: 2
+updates:
+  # Maintain dependencies for GitHub Actions
+  - package-ecosystem: "github-actions"
+    directories:
+      - "/"
+    schedule:
+      interval: "monthly"
+    commit-message:
+      prefix: "dependencies: "
+      include: scope
+    groups:
+      actions:
+        patterns:
+          - "*"