add links/hrefs to head

[dkuntze]

example page: https://www.shredit.com/en-us/secure-shredding-services/paper-shredding-services source:

<link rel="alternate" hreflang="en-US" href="https://www.shredit.com/en-us/secure-shredding-services/paper-shredding-services"/>
<link rel="alternate" hreflang="x-default" href="https://www.shredit.com/en-us/secure-shredding-services/paper-shredding-services"/>
<link rel="alternate" hreflang="en-CA" href="https://www.shredit.com/en-ca/secure-shredding-services/paper-shredding-services"/>
<link rel="alternate" hreflang="fr-CA" href="https://www.shredit.com/fr-ca/service-dechiquetage-securitaire/services-dechiquetage-document"/>

I think we would source the alts via metadata entry and/or run a query to see if any other pages match paths