feat: expose network listeners to nginx templates for all process types

This change allows users to specify a custom nginx.conf.sigil that can expose non-web process types to the outside world in addition to the web process type.

Closes #3258

docs/development/plugin-triggers.md

@@ -678,7 +678,7 @@ set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 
 - Description: Return the listeners (host:port combinations) for a given app container
 - Invoked by: `internally triggered by a deploy`
-- Arguments: `$APP`
+- Arguments: `$APP $PROCESS_TYPE`
 - Example:
 
 ```shell