docs(nodejs-express-server): fix default port number in README (#20706)

Update README to correctly show 8080 as the default port instead of 3000. This matches the actual server configuration in config.js where the server listens on port 8080 by default.

Author: gus-costa

modules/openapi-generator/src/main/resources/nodejs-express-server/README.mustache

@@ -16,7 +16,7 @@ The code was written on a mac, so assuming all should work smoothly on Linux-bas
 Assuming you have Java (1.8+), and [have the jar](https://github.com/openapitools/openapi-generator#13---download-jar) to generate the application, run:
 ```java -jar {path_to_jar_file} generate -g nodejs-express-server -i {openapi yaml/json file} -o {target_directory_where_the_app_will_be_installed} ```
 If you do not have the jar, or do not want to run Java from your local machine, follow instructions on the [OpenAPITools page](https://github.com/openapitools/openapi-generator). You can run the script online, on docker, and various other ways.
-2. Go to the generated directory you defined. There's a fully working NodeJS-ExpressJs server waiting for you. This is important - the code is yours to change and update! Look at config.js and see that the settings there are ok with you - the server will run on port 3000, and files will be uploaded to a new directory 'uploaded_files'.
+2. Go to the generated directory you defined. There's a fully working NodeJS-ExpressJs server waiting for you. This is important - the code is yours to change and update! Look at config.js and see that the settings there are ok with you - the server will run on port 8080, and files will be uploaded to a new directory 'uploaded_files'.
 3. The server will base itself on an openapi.yaml file which is located under /api/openapi.yaml. This is not exactly the same file that you used to generate the app:
 I. If you have `application/json` contentBody that was defined inside the path object - the generate will have moved it to the components/schemas section of the openapi document.
 II. Every process has a new element added to it - `x-eov-operation-handler: controllers/PetController` which directs the call to that file.
@@ -35,8 +35,8 @@ Unfortunately, I have not written any unit-tests. Those will come in the future.
 (Assuming no changes were made to config.js)
 
 1. API documentation, and to check the available endpoints:
-http://localhost:3000/api-docs/. To
-2. Download the openapi.yaml document: http://localhost:3000/openapi.
+http://localhost:8080/api-docs/. To
+2. Download the openapi.yaml document: http://localhost:8080/openapi.
 3. Every call to an endpoint that was defined in the openapi document will return a 200 and a list of all the parameters and objects that were sent in the request.
 4. Endpoints that require security need to have security handlers configured before they can return a successful response. At this point they will return [ a response code of 401](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/401).
 5. ##### At this stage the server does not support document body sent in xml format.