Allow container listen port configuration with the `PORT` environment variable

Hi there,

I'm trying to run the swagger-editor docker image along with the swagger-ui image in a kubernetes pod.

I've upgraded the image from 4.x to 5.x and swagger editor was not reachable anymore.

+        image: docker.io/swaggerapi/swagger-editor:v5.1.0
         # See also https://github.com/swagger-api/swagger-editor
         env:
-          - name: BASE_URL
-            value: "/editor"
+          #- name: BASE_URL
+          #  value: "/editor"
           - name: QUERY_CONFIG_ENABLED
@@ -45,7 +45,10 @@ spec:
         ports:
           - name: http-editor
             protocol: TCP
-            containerPort: 8080
+            # NOTE PORT environment variable is ignored
+            # See also https://github.com/swagger-api/swagger-editor/issues/5700
+            containerPort: 80

-        image: docker.io/swaggerapi/swagger-editor:v4.11.2
+        image: docker.io/swaggerapi/swagger-editor:v5.1.0

With 5.x the swagger-ui container can no longer be configured with PORT and BASE_URL environment variables.
The nginx entrypoint is now overwritten. The EXPOSE 8080 is invalid because nginx defaults to port 80.

https://github.com/swagger-api/swagger-editor/blob/v5.1.0/Dockerfile
https://github.com/swagger-api/swagger-editor/blob/v4.11.2/Dockerfile

Is this on purpose ?

Compare the v5.1.0 and v4.11.2 Dockerfiles linked in the issue, focusing on the nginx entrypoint, EXPOSE declaration, and PORT or BASE_URL handling. Verify how the v5 container starts and confirm the container becomes reachable on the configured PORT while preserving the documented configuration behavior.