Add publish workflow

.github/workflows/publish.yml

@@ -0,0 +1,24 @@
+name: Docker Build and Publish
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - run: docker build -t ghcr.io/quiltmc/javadoc-publish:latest -t ghcr.io/quiltmc/javadoc-publish:${GITHUB_SHA} .
+      - run: docker push ghcr.io/quiltmc/javadoc-publish:latest
+      - run: docker push ghcr.io/quiltmc/javadoc-publish:${GITHUB_SHA}