Fixes #911: Document how to disable MailHog correctly.

docs/extras/mailhog.md

@@ -1,3 +1,11 @@
 By default, Drupal VM redirects all PHP emails to [MailHog](https://github.com/mailhog/MailHog) (instead of sending them to the outside world). You can access the MailHog UI at `http://drupalvm.dev:8025/` (or whatever domain you have configured in `config.yml`).
 
-You can override the default behavior of redirecting email to MailHog by editing or removing the `php_sendmail_path` inside `config.yml`, and you can choose to not install MailHog at all by removing it from `installed_extras` in `config.yml`.
+## Disable MailHog
+
+If you don't want to use MailHog, you can set the following override (back to PHP's default, as defined in the [`geerlingguy.php`](https://github.com/geerlingguy/ansible-role-php#role-variables) role) in your `config.yml` file:
+
+```
+php_sendmail_path: "/usr/sbin/sendmail -t -i"
+```
+
+After doing this, you can also prevent MailHog's installation by removing `mailhog` from the `installed_extras` list.