Make nginx more clear that changing the port is 'dangerous' (#4880)

* Make nginx more clear that changing the port is 'dangerous'
See https://github.com/inventree/InvenTree/issues/4859#issuecomment-1560025566

* also add note to prod docker-compose

docker/production/docker-compose.yml

@@ -73,6 +73,10 @@ services:
         container_name: inventree-server
         # If you wish to specify a particular InvenTree version, do so here
         image: inventree/inventree:${INVENTREE_TAG:-stable}
+        # Only change this port if you understand the stack.
+        # If you change this you have to change:
+        # - the proxy settings (on two lines)
+        # - only change the exposed port - eg `1338:8000` if you want to expose the server on port 1338
         expose:
             - 8000
         depends_on:

docker/production/nginx.prod.conf

@@ -24,8 +24,7 @@ server {
         proxy_buffering off;
         proxy_request_buffering off;
 
-        # Change 'inventree-server' to the name of the inventree server container,
-        # and '8000' to the INVENTREE_WEB_PORT (if not default)
+        # Do not touch this unless you have a specific reason - this and the docker-compose need to match
         proxy_pass http://inventree-server:8000;
     }