ci: add workflow to lint PR diffs using vale

Author: f-hollow

.github/workflows/pr-lint-vale.yml

@@ -0,0 +1,13 @@
+name: reviewdog
+on: [pull_request]
+
+jobs:
+  vale:
+    name: runner / vale
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: errata-ai/[email protected]
+        with:
+          reporter: github-pr-check
+          fail_on_error: true