build: Add workflow file to build and push docker image to docker hub

.github/workflows/build-push-docker-image.yml

@@ -0,0 +1,34 @@
+name: Build and Push Docker image
+
+on:
+  push:
+    branches:
+      - "docker-image"
+
+jobs:
+  prepare-dataset:
+    runs-on: ubuntu-latest
+    environment: docker-container-registry
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: Build and Push Docker Image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: getwithashish/expchatbot:latest
+
+      - name: Image digest
+        run: echo ${{ steps.docker_build.outputs.digest }}