added coverage workflow

.github/workflows/coverage.yml

@@ -0,0 +1,24 @@
+name: Coverage
+on: [push, pull_request]
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.8'
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install pytest pytest-cov
+          pip install -e .
+      - name: Run tests with coverage
+        run: |
+          pytest --cov=tirith tests/
+      - name: Upload coverage report
+        uses: actions/upload-artifact@v3
+        with:
+          name: coverage-report
+          path: coverage.xml