So as to transition relatively seemlessly to the new site, we can use the
Hugo Alias functionality to put a number of HTML redirects in place to
translate between `/old-wiki/<original_link>` and the new page location.

We are hoping to combine this with URL rewriting on wiki.apertis.org to
redirect requests for pages formerly served there into the redirect
structure.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>