docs: fix how-to-develop-producer-platform (#8482)

docs/dev/how-to-develop-producer-platform.md

@@ -12,15 +12,16 @@ You should have two kind of shell:
   (this simply sets some environment variables that will overides the one in .env)
 
 To develop, on producers plateform, you can then us a shell for openfoodfacts-pro and simply do a `make dev` and everything as usual.
+(in case you don't see CSS you might run `make build_lang` in the *pro shell*)
 
 If you need to work on product import/export, or interacting with public platform,
-you have to start postgres and the minion on off side.
+you have to start postgres, mongodb and the minion on off side.
 That is, in a *non pro* shell, run `docker-compose up postgres minion mongodb`.
 
 Note that the setup does not currently support running the http server for both public and pro platform at the same time.
 So as you need the public platform:
-- in your *pro shell*, run a `docker-compose stop backend`
-- in your *non pro shell*, run a `docker-compose up backend`
+- in your *pro shell*, run a `docker-compose stop frontend`
+- in your *non pro shell*, run a `docker-compose up frontend`
 Now `openfoodfacts.localhost` is the public database.
 Of course, do this inside-out to access the pro http server.