Include JWT license reference to installing-nginx-docker.md

As suggested by @alessfg

Author: mjang

content/nginx/admin-guide/installing-nginx/installing-nginx-docker.md

@@ -316,7 +316,7 @@ This command also allows viewing the port mappings set in the previous step: the
 As NGINX Plus is a commercial offering, NGINX Plus Docker images are not available at Docker Hub, so first you will need to create an NGINX Plus Docker image.
 
 > **Note:** Never upload your NGINX Plus images to a public repository such as Docker Hub. Doing so violates your license agreement.
-
+∂no∂
 To generate a custom NGINX Plus image:
 
 1. Create the Docker build context, or a Dockerfile, for example:
@@ -335,14 +335,14 @@ To generate a custom NGINX Plus image:
 
     - no files are copied from the Docker host as a container is created: you can add `COPY` definitions to each Dockerfile, or the image you create can be used as the basis for another image
 
-3. Log in to [MyF5 Customer Portal](https://account.f5.com/myf5) and download your *nginx-repo.crt* and *nginx-repo.key* files. For a trial of NGINX Plus, the files are provided with your trial package.
+3. Log in to [MyF5 Customer Portal](https://account.f5.com/myf5). As noted in the [Prerequisites](#prerequisites] and download your *nginx-repo.crt*, *nginx-repo.key*, and **JSON Web Token** files. In addition, download the corresponding For a trial of NGINX Plus, the files are provided with your trial package.
 
 4. Copy the files to the directory where the Dockerfile is located.
 
 5. Create a Docker image, for example, `nginxplus` (note the final period in the command).
 
     ```shell
-    docker build  --no-cache --secret id=nginx-key,src=nginx-repo.key --secret id=nginx-crt,src=nginx-repo.crt -t nginxplus .
+    docker build  --no-cache --secret id=nginx-key,src=nginx-repo.key --secret id=nginx-crt,src=nginx-repo.crt --secret id=nginx-jwt,src=license.jwt -t nginxplus .
     ```
 
     The `--no-cache` option tells Docker to build the image from scratch and ensures the installation of the latest version of NGINX Plus. If the Dockerfile was previously used to build an image without the `--no-cache` option, the new image uses the version of NGINX Plus from the previously built image from the Docker cache.