Add GitHub Actions workflow to build and push multi-arch Docker image

.github/workflows/docker.yml

@@ -0,0 +1,48 @@
+name: Build and Push Docker Image (Multi-Arch)
+
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - '*'
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository }}
+
+      - name: Build and push Docker image (multi-arch)
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./Dockerfile
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}

README.md

@@ -178,11 +178,14 @@ print(result.text_content)
 
 ### Docker
 
+We recommend you to use a specific tag, just as follow :
+
 ```sh
-docker build -t markitdown:latest .
-docker run --rm -i markitdown:latest < ~/your-file.pdf > output.md
+docker run --rm -i ghcr.io/microsoft/markitdown:v0.1.2 < ~/your-file.pdf > output.md
 ```
 
+It is nevertheless possible to use the `latest` or `main` tag.
+
 ## Contributing
 
 This project welcomes contributions and suggestions. Most contributions require you to agree to a