ci: add basic GitHub Actions workflow with vint for the plugin (distributability milestone)

Author: cvquesty

.github/workflows/ci.yml

@@ -0,0 +1,13 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install vint
+        run: pip install vim-vint
+      - name: Run vint
+        run: vint --style ./