Add basic GitHub action

.github/workflows/python-app.yml

@@ -0,0 +1,29 @@
+name: Python application
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up PDM
+        uses: pdm-project/setup-pdm@v4
+        with:
+          python-version: 3.12
+      - name: Install dependencies
+        run: |
+          pdm sync -d -G testing
+      - name: Lint
+        run: |
+          pdm lint
+      - name: Test
+        run: |
+          pdm test