added code for pushing docker image into dockerhub

.github/workflows/cicd.yml

@@ -10,3 +10,17 @@ jobs:
     - name: Build Docker image
       run: |
         docker build -t my-docker-repo .
+    - name: Login to Docker Hub
+      uses: docker/login-action@v3
+      with:
+        username: ${{ secrets.DOCKERHUB_USERNAME }}
+        password: ${{ secrets.DOCKERHUB_TOKEN }}
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v3
+    - name: Build and push
+      uses: docker/build-push-action@v5
+      with:
+        context: .
+        file: ./Dockerfile
+        push: true
+        tags: ${{ secrets.DOCKERHUB_USERNAME }}/pythonapp:latest