Fully follow Google language guidelines #116
Description
https://support.google.com/webmasters/answer/189077?hl=en
Currently I don't think we implement these correctly especially the alternative version. We'd need to do some updating of src/layouts/Header-en.js and src/layouts/Header-es.js to properly reference the alternatives correctly.
We should also fix the sitemap, which is possible but will requires us to use some custom logic with GraphQL queries for English vs Spanish