[Docs] Issue when publishing schema

Hey there!
For some reason when trying to [publish the schema](https://www.apollographql.com/docs/tutorial/production.html#publish) I was getting this error:
```
✔ Loading Apollo Project
✖ Uploading service to Engine
→ No service found to link to Engine
Error: No service found to link to Engine
at Task.task (~/.npm/_npx/32532/lib/node_modules/apollo/lib/commands/service/push.js:17:31)
at Promise.resolve.then.then.skipped (~/.npm/_npx/32532/lib/node_modules/apollo/node_modules/listr/lib/task.js:167:30)
at
```

This is what I did, and didn't work:
- Had my `.env` file with the `ENGINE_API_KEY` set.
- Tried removing the `sevice:` prefix from the value of the variable
- Tried restarting the server
- Tried running `npx apollo service:check && npx apollo service:push` from the `/server` folder
- Double and tripled checked the API key

Finally I gave up and had to type the parameters directly on the `service:push` command.

Is this only my issue?

Inizia con le istruzioni per la pubblicazione in produzione collegate nell’issue e con la configurazione di `/server`, quindi riproduci i comandi `npx apollo service:check` e `service:push` usando `.env` e `ENGINE_API_KEY`. Il lavoro è completato quando il flusso di pubblicazione dello schema documentato nel tutorial funziona oppure le istruzioni spiegano chiaramente i parametri e la configurazione richiesti.

Scritto dal modello di indicizzazione a partire dal testo della issue.