Small SODA doc clarification

Author: cjbj

doc/api.md

@@ -5357,7 +5357,7 @@ Property              | Description
 *readonly String createdOn*    | The creation time of the document as a string in the UTC time zone using an ISO8601 format such as '2018-07-11T01:37:50.123456Z' or '2018-07-11T01:37:50.123Z'. By default, SODA sets this automatically.
 *readonly String key*          | A unique key value for this document.  By default, SODA automatically generates the key.
 *readonly String lastModified* | Last modified time of the document as a string in the UTC time zone using an ISO8601 format such as '2018-07-11T01:37:50.123456Z' or '2018-07-11T01:37:50.123Z'. By default, SODA sets this automatically.
-*readonly String mediaType*    | An arbitrary string value designating the content media type.  The recommendation when creating documents is to use a MIME type for the media type. By default, collections store only JSON document content and this property will be 'application/json'.  This property will not be defined if the media type is unknown, which will only be in the rare case when a collection was created to store mixed or non-JSON content on top of a pre-existing database table, and that table has NULLs in its `mediaType` column.
+*readonly String mediaType*    | An arbitrary string value designating the content media type.  The recommendation when creating documents is to use a MIME type for the media type. By default, collections store only JSON document content and this property will be 'application/json'.  This property will be null if the media type is unknown, which will only be in the rare case when a collection was created to store mixed or non-JSON content on top of a pre-existing database table, and that table has NULLs in its `mediaType` column.
 *readonly String version*      | Version of the document.  By default, SODA automatically updates the version each time the document is changed.
 
 These properties were added in node-oracledb 3.0.