Import checks from Jekyll

[Frank Taillandier]

Discussed in jekyll/jekyll#6391

/cc @sverrirs

[Ashwin Maroli]

https://github.com/jekyll/jekyll/blob/4c97f5ef222465916c499f5d7a1bace9d1a40650/lib/jekyll/renderer.rb#L211-L213

    # Set page content to payload and assign pager if document has one.
    #
    # Returns nothing
    private
    def assign_pages!
      payload["page"] = document.to_liquid
      payload["paginator"] = if document.respond_to?(:pager)
                               document.pager.to_liquid
                             end
    end

[Parker Moore]

@ashmaroli That should be in a Hook, I think.

These could both be hooks, I guess.