updated documentation to allow for one or more identifiers to be provided for a contact

Author: micheldumontier

versions/3.0.0.md

@@ -288,7 +288,7 @@ This object MAY be extended with [Specification Extensions](#specificationExtens
 Field Name | Type | Description
 ---|:---:|---
 <a name="contactRole"></a>x-role | `enum` | **REQUIRED** Indicate the role of the contact. Values can be: `responsible organization`,`responsible developer`,`contributor`,`support`.
-<a name="contactId"></a>x-id | `string` | **SHOULD** Provide a unique identifier for the contact.
+<a name="contactId"></a>x-id | [`string`] | **SHOULD** One or more unique identifiers for the contact.
 
 
 ##### Contact Object Example: