Add change tagging

[JamesMBligh]

Description
To allow for greater ability to review the changes in a specific version of the standards compared to the previous version there is a need to introduce greater granularity in the changes applied to a specific version of the standards.

Related Work Items
There are two suggested options for achieving this outcome:

1. Produce an automated diff script that can generate more detailed release notes that can then be published in the release notes section
2. Add tagging to the raw files so that changes can be tagged an inline highlighting can show the changes that have been made

Option 2 would appear to be a much better experience but may be very difficult to achieve for the parts of the standards that are generated from swagger using widdershins. The best solution may be a combination of tagging for hand written markdown and a list of specific changes preceding swagger generated markdown sections.

[perlboy]

It is unclear what value is derived from reimagining diff within a source control system. The issue highlighted since the beginning has been the lack of repeatable builds combined with the use of a source control system as a file system. Without more information regarding this proposal it is difficult to make comment on whether it is likely to rectify the issue at hand.