Add get document type hinting for type (#1632)
Add get document type hinting for type (#1632)

Fix getDocement() PHPDoc and add type hinting.
miniplay/Elastica,giovannialbero1992/Elastica,p365labs/Elastica,giovannialbero1992/Elastica,ruflin/Elastica,miniplay/Elastica,p365labs/Elastica