Merge pull request #388 from rjc123/under-score

Remove double underscore for bouncer
Complete stub setup
Merge pull request #389 from rjc123/newsites

Complete stub setup
Merge pull request #390 from rjc123/newmappings

Add mappings for GAD
Make official documents part of TNA

Transition keys on site title to determine whether something is an
org in its own right. These sites aren't, so we need to make them
subordinate to TNA.
Merge pull request #391 from alphagov/make-offdocs-part-of-tna

Make official documents part of TNA
Add archive mappings for GAD
Resolve zendesk enquiry - MOD mappings