Summary:
The goal of this PR is to place greater emphasis on the blog as a destination.
The dark Hero from the landing page is now present in the blog as well, and the content is front and center.
The sidebar has been removed. It is not necessary to show a list of recent blog posts in the sidebar when the blog landing page shows the same number of posts along with short excerpts.
The prev/next links have swapped positions, and will now display "Older posts" and "Newer posts".
The excerpts have been stripped of formatting and they are now consistent across the blog landing page and the OpenGraph metatags. Fixes#10597.
A signup form for the new React Native newsletter has been added to the footer.
Newsletter signup form in footer:

Blog landing page:
, with some additional recommendations that can be ignored for now.
> Congratulations!
>
> [Valid Atom 1.0] This is a valid Atom 1.0 feed.
> Recommendations
>
> This feed is valid, but interoperability with the widest range of feed readers could be improved by implementing the following recommendations.
> line 2, col
Closes https://github.com/facebook/react-native/pull/10611
Differential Revision: D4097381
Pulled By: mkonicek
fbshipit-source-id: 8d2e18923358d1903b2715b00c48680b0c4dff68
This will prevent us from having pages on the site that just show error
stack traces -- instead, Travis will fail with an error and we'll
notice sooner.
I cleaned up this logic to use promises which was eay easier to track
for the error behavior and should be simpler to follow regardless.