Fix automatic registries help

Applies to all automatic registries. Examples here used the automation operations registry.

• Register a custom

  (e.g. Automation Operations)
  => should not contain "a"

• you can run nuxeo studio synchronize
  => command does not exist and should be replaced by nuxeo studio export

• and they are pushed here
  => and they will be pushed here

• This registry should not be edited by hand for common use cases, you can declare additional Automation Operations in the similar registry not reserved for Nuxeo CLI.
  => Do not edit this registry unless you wish to remove some of the declared operations; Nuxeo CLI could override your changes. To declare additional automation operations manually, please use the option found in the Registries menu instead.

• This registry is read-only by default, it should not be edited manually as it is overwritten by subsequent synchronizations from an external tool, but you can still switch to edit mode if needed. You can also move its content to the corresponding manual registry that is not impacted by any external tool.
  => This registry is read-only by default. It should not be edited manually, as it can be overwritten by subsequent synchronizations from an external tool. You can switch to edit mode if needed, but if you intend to keep your changes we rather recommend moving its content to the corresponding manual registry that will not be impacted by any external tool.