feat(#4): Add docker support

.github/workflows/docker.yml

@@ -0,0 +1,56 @@
+name: Docker
+
+on:
+  pull_request:
+    branches:
+      - main
+  push:
+    branches:
+      - main
+    tags:
+      - "v*.*.*"
+
+env:
+  IMAGE_NAME: jcreek23/open-network-diagram
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Docker Hub
+        if: github.event_name == 'push'
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: docker.io/${{ env.IMAGE_NAME }}
+          tags: |
+            type=raw,value=latest,enable={{is_default_branch}}
+            type=sha,prefix=sha-
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+
+      - name: Build (PR) / Build+Push (push)
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: Dockerfile
+          push: ${{ github.event_name == 'push' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max