Enable the Jetpack "Subscribe via Email" widget to Rosetta blog

[netweb]

Currently the "Subscribe via Email" widget is enabled on "teams" sites but not the Rosetta news blog:

• ​https://en-au.wordpress.org/news/
• ​https://en-au.wordpress.org/team/

We should make it as easy as possible for users to subscribe to localised news.

Related: ​https://make.wordpress.org/polyglots/2017/02/16/local-wordpress-org-sites-content-lets-gather-the-data/

[ocean90]

The main news blog also doesn't have this enabled, see #727. Once we have it there we can consider enabling it for all sites.

In the design of most wporg sites, breadcrumbs are not needed when the level is less than 3. Therefore, a filter is usually applied to the breadcrumbs block to make the breadcrumbs an empty array. If this early return is not implemented, it would still return a div that occupies space.

See ​https://github.com/WordPress/Learn/pull/2598/commits/6fa130a1dd222cf020da700f0afb9b65cef33643