feat(docs): add section pager (disable by default)
feat(docs): add section pager (disable by default)

Disable docs prev/next pager unless `docs_section_pager = true` in
`params.toml`.

Requires setting `sections_weight = 01` in front matter of docs pages to
control the order of their appearance in the prev/next links. Otherwise,
prev/next links are generated by Hugo based on chronological date order
- which will be an invalid order in the case of docs.

See https://github.com/gohugoio/hugo/issues/2494

gcushen/hugo-academic,gcushen/hugo-academic,gcushen/hugo-academic,gcushen/hugo-academic