The Nuxeo Platform has a trash feature: deleted document are actually not deleted but moved "in the trash", before being really deleted. See more information about this feature in the user guide.
To enable the trash on your document type, you need either to assign him the default life cycle (which is the case if you don't configure it) or, if you created a custom life cycle, to provide delete transitions to the deleted state, from each other state. Moreover, in order to be able to restore documents, you must provide a undelete transition from the deleted state to another state in the lifecycle.
See the sample below:
Related Documentation
Documents in Nuxeo Studio Content Repository Available Facets Life cycle