feat: Add GitHub Actions CI workflow

Configure automated checks for pull requests including:

- Linting the Helm chart.
- Building the exporter Docker image.
- A placeholder for future tests.

.github/workflows/ci.yaml

@@ -0,0 +1,57 @@
+name: CI
+
+on:
+  pull_request:
+    branches: ["main"] # Or your main development branch
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  validate-chart:
+    name: Validate Helm Chart
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      - name: Set up Helm
+        uses: azure/setup-helm@v3
+        with:
+          version: v3.10.0
+
+      - name: Helm Lint
+        run: helm lint ./charts/iperf3-monitor
+
+  build:
+    name: Build Docker Image
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v4
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+      - name: Build Docker image
+        uses: docker/build-push-action@v4
+        with:
+          context: ./exporter
+          push: false # Do not push on PRs
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
+  test:
+    name: Run Tests
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v3
+
+      # Replace this step with your actual test command(s)
+      - name: Placeholder Test Step
+        run: echo "No tests configured yet. Add your test commands here."