Add workflow for dockerfile

.github/Dockerfile

@@ -0,0 +1,10 @@
+FROM coqorg/coq:8.17.1
+
+ENV NCPUS=4
+ENV OPAMYES="true"
+ENV OPAMJOBS=$NCPUS
+
+RUN opam repo add coq-released https://coq.inria.fr/opam/released \
+    && opam update \
+    && opam install coq-equations coq-menhirlib menhir ppx_inline_test \
+    && eval $(opam env)

.github/workflows/docker.yaml

@@ -0,0 +1,41 @@
+name: Publish Docker Image for CI
+
+on: workflow_dispatch
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  build-and-push-image:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      attestations: write
+      id-token: write
+    steps:
+    - name: repo checkout
+      uses: actions/checkout@v3
+
+    - name: container registry log in
+      uses: docker/login-action@v3
+      with:
+        registry: ${{ env.REGISTRY }}
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: metadata extraction
+      id: meta
+      uses: docker/metadata-action@v5
+      with:
+        images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+    - name: Build and push Docker image
+      uses: docker/build-push-action@v5
+      with:
+        context: .
+        file: .github/Dockerfile
+        push: true
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}