Add DCO check.

Author: katzdm

.github/workflows/dco-check.yaml

@@ -0,0 +1,25 @@
+name: DCO check
+
+on:
+  pull_request:
+    types:
+      - "opened"
+      - "reopened"
+      - "synchronize"
+      - "labeled"
+      - "unlabeled"
+
+jobs:
+  commits_check_job:
+    runs-on: ubuntu-latest
+    name: Commits Check
+    steps:
+      - name: Get PR Commits
+        id: "get-pr-commits"
+        uses: tim-actions/get-pr-commits@master
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+      - name: DCO Check
+        uses: tim-actions/dco@master
+        with:
+          commits: ${{ steps.get-pr-commits.outputs.commits }}