chore: add CI workflow

Author: JKRhb

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: Build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  merge_group:
+    branches: [ main ]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dart-lang/setup-dart@v1
+
+      - name: Install dependencies
+        run: dart pub get
+
+      - name: Verify formatting
+        run: dart format --output=none --set-exit-if-changed .
+
+      - name: Analyze project source
+        run: dart analyze
+
+      - name: Run tests with coverage
+        run: dart run coverage:test_with_coverage
+
+      - uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          file: coverage/lcov.info
+          name: Upload to codecov.io
+          verbose: true