Add infrastructure for automatic building of MasKIT docker image.

The image rebuild is triggered when anything in the `docker` directory
changes.

.github/workflows/maskit_docker.yml

@@ -0,0 +1,30 @@
+name: maskit-docker
+
+on:
+  push:
+    paths:
+      - 'docker/**'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      attestations: write
+      id-token: write
+    steps:
+      -
+        name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{github.actor}}
+          password: ${{secrets.GITHUB_TOKEN}}
+      -
+        name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: "{{defaultContext}}:docker"
+          push: true
+          tags: ghcr.io/ufal/maskit:latest

docker/rebuild.md

@@ -0,0 +1,7 @@
+# Rebuild the MASkit Docker image
+
+The goal of this file is just to force a rebuild of the MASKit docker image,
+which is being built when any file in the `docker` directory changes.
+
+## Lastest Rebuild:
+- Mon Jan  6 15:30:58 CET 2025