Add CI config

.github/workflows/ci.yml

@@ -0,0 +1,20 @@
+on:
+  push:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.13
+      - uses: taiki-e/install-action@just
+      - name: Install uv
+        uses: astral-sh/setup-uv@v3
+
+      - name: Set up
+        run: uv sync
+      - name: Lint
+        run: uv run just lint