Add missing periods

Existing Wording:

The following data-elements are mandatory (i.e data MUST be present) or must be supported if the data is present in the sending system (Must Support definition).

Each Bundle must have:
1. A type code of “message”
2. An entry for the MessageHeader
3. An entry for the event or request resource reference by ‘MessageHeader.focus’

Proposed Wording:

The following data-elements are mandatory (i.e\. data MUST be present) or must be supported if the data is present in the sending system (Must Support definition)\.

Each Bundle must have:
1\. A type code of “message”\.
2\. An entry for the MessageHeader\.
3\. An entry for the event or request resource reference by ‘MessageHeader\.focus’\.