Add extra redirect for homepage

The redirection from the old wiki redirects `wiki.apertis.org/*` to
`www.apertis.org/old-wiki/*`, currently this works when a specific page is
specified, but not when redirected to `www.apertis.org/old-wiki`.

Add in an extra alias to handle this case.

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

content/_index.md

@@ -5,7 +5,8 @@ weight = 100
 title = "Home Page"
 
 aliases = [
-    "/old-wiki/Main_Page"
+    "/old-wiki/Main_Page",
+    "/old-wiki"
 ]
 +++