Redirect https://wiki.cam.ac.uk/raven and https://raven.cam.ac.uk/project/ to https://docs.raven.cam.ac.uk/

Depends on #2 (closed).

For https://wiki.cam.ac.uk/raven:

1. Use https://wiki.cam.ac.uk/raven/Special:AllPages and https://wiki.cam.ac.uk/raven/Special:Export to get an XML dump of the history of all pages. Place these in a new public GitLab project called "Wiki Archive" under uis/devops/raven and archive it.
2. Replace all pages on https://wiki.cam.ac.uk/ with a banner indicating that documentation has moved to https://docs.raven.cam.ac.uk/

For https://raven.cam.ac.uk/project/

1. Delete contents of index.html and replace with HTML <meta> redirect to https://docs.raven.cam.ac.uk/.
2. Delete other files under /project/.