doc: fix description of modified update function

src/entity-manager/MongoEntityManager.ts

@@ -208,7 +208,7 @@ export class MongoEntityManager extends EntityManager {
     }
 
     /**
-     * Updates entity partially. Entity can be found by a given conditions.
+     * Updates entities partially. Entities can be found by a given conditions.
      * Unlike save method executes a primitive operation without cascades, relations and other operations included.
      * Executes fast and efficient UPDATE query.
      * Does not check if entity exist in the database.