Update Jira DVCS docs
What does this MR do and why?
Update Jira DVCS docs in preparation for removal of DVCS support for Jira Cloud, see Deprecation of Jira GitHub Enterprise DVCS Inte... (#362168 - closed)
Update Jira DVCS docs in preparation for removal of DVCS support for Jira Cloud, see Deprecation of Jira GitHub Enterprise DVCS Inte... (#362168 - closed)