Add initial GitHub Actions workflow YAML file.

.github/workflows/python.yaml

@@ -0,0 +1,28 @@
+name: Python Build
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.11
+
+      - name: Install dependencies
+        run: pip install -r requirements.dev.txt
+
+      - name: MyPy
+        run: mypy bzhr
+
+      - name: Black
+        run: black --check bzhr
+
+      - name: isort
+        run: isort --check bzhr
+