chore: add GitHub PR validation workflows (#86)

chore: add PR title validation workflow
chore: add config for GitHub DCO app

Author: spah-soptim

.github/dco.yml

@@ -0,0 +1,2 @@
+require:
+  members: false

.github/workflows/pr-title.yml

@@ -0,0 +1,26 @@
+name: PR Title Check
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - reopened
+      - synchronize
+
+permissions:
+  pull-requests: read
+
+jobs:
+  validate-pr-title:
+    name: Validate PR title
+    runs-on: ubuntu-slim
+    permissions:
+      pull-requests: read
+    steps:
+      - name: Validate PR title
+        uses: amannn/action-semantic-pull-request@48f256284bd46cdaab1048c3721360e808335d50 # v6.1.1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          requireScope: false