Added term for Data Centre

Reassigned to @ChadMalchow

@richardp I do not have access to merge this. @ernstvn can you help here?

mentioned in commit b0d900d9

Status changed to merged

@richardp This should be clarified further as the term Data Center isn't unique to Atlassian... They seem to be calling it a "Data Center" deployment option https://www.atlassian.com/enterprise/data-center