Updating link for /browse/housing in the footer

The browse category has been renamed to /browse/housing-local-services.

I'll also update the following:

* https://github.com/alphagov/spotlight/blob/master/app/server/templates/page-components/footer_top.html
* https://github.com/alphagov/government-service-design-manual/blob/master/_includes/layouts/_footer_top.html
* https://github.com/alphagov/transformation-dashboard/blob/master/_includes/layouts/_footer_top.html
* https://github.com/alphagov/fco-services-node/blob/master/views/partials/_footer_top.ejs