Stop redirects from showing up on manual page
Stop redirects from showing up on manual page

Redirects are also showing up on the homepage. Because they don't have
a title they're displayed as an empty list item. This commit makes sure
we don't include things without titles. This then enables us to be less
defensive in the `sort_by` block.

alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs,alphagov/govuk-developer-docs