Preload the first page's posts

[ryelle]

Only on the homepage, load the first page of API responses to speed up the page render.

The logic to pre-render any initial response is out-of-scope for this ticket, but could happen eventually.

[ryelle]

Considering this done. Most commonly entered-on things will pre-load:

• Home page
• Single posts
• Single pages
• A page set as front
• The posts on the posts page (when page-as-front)

Basically only archive pages don't preload, since their queries are harder to pre-compute.