Add National Records of Scotland

[greencardamom]

Main site:
https://webarchive.nrscotland.gov.uk

Example archive:
https://webarchive.nrscotland.gov.uk/20170409044816/http://www.gov.scot/Resource/Doc/285746/0087034.pdf

Example API:
https://webarchive.nrscotland.gov.uk/timemap/http://www.gov.scot/Resource/Doc/285746/0087034.pdf