Add previous/next links

Seems quite simple to implement:

• at the entry level, navigate to the next entry
• at the initial page level, navigate to the next initial page
• locate entry nodes as children of initial pages
• locate initial pages as children of the main page
• possibly add the link.rel=prev/next head data to support that navigation.

Consider, however, that although prev/next were recommended by Google in 2011 (cf. https://developers.google.com/search/blog/2011/09/pagination-with-relnex...) , in 2023, they are documented as no longer relevant: that same page mentions " rel=prev/next is not an indexing signal anymore". Another page https://developers.google.com/search/docs/specialty/ecommerce/pagination... mentions "In the past, Google used
and
to identify next page and previous page relationships. Google no longer uses these tags, although these links may still be used by other search engines.".

In addition the WHATWG decided to drop them entirely in 2011 : https://lists.w3.org/Archives/Public/public-html/2011Feb/att-0481/issue-...

All in all, adding these head links seems pointless.

After checking various solutions, the recommended approach is not to bundle the feature in G2, but use contrib:

• use the popular Entity Pager module
• the main paging should be using a sort on the "title", then "g2 expansion" fields, filtering on "g2_entry" nodes
• the "all" page should be the the main g2 page

Automatically closed - issue fixed for 2 weeks with no activity.