adds Docker Hub login to workflow

.github/workflows/docker.yml

@@ -52,6 +52,12 @@ jobs:
         run: |
           Write-Output ${{ env.VERSION }}
           ./.github/scripts/UpdateAssemblyVersion.ps1 ${{ env.VERSION }}
+      # Login to Docker
+      - name: Login to Docker
+        uses: azure/docker-login@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_TOKEN }}
       # Build the solutions in the docker image
       - name: Build Solution
         shell: powershell