Make twentynineteen the default theme

[jorbin]

After [43808], we can now make twentynineteen the default

[desrosj]

Tested 45152.diff​ and Twenty Nineteen is correctly applied as the default theme for a new install.

[jorbin]

In 43809:

Bundled Theme: Make twentynineteen the default theme.

After [43808], we can now make twentynineteen the default theme. Twentyseventeen has been a great default, but 5.0 and twentynineteen is guten.

Fixes #45152.

[jorbin]

reopening for merge to trunk when trunk is open again

[SergeyBiryukov]

The help text on wp-admin/nav-menus.php needs an update as well, also the sidebars_widgets option.

See [38919] and [38920] for Twenty Seventeen.

[SergeyBiryukov]

In 45152.2.diff​:

• Update nav menus help text.
• Update sidebars_widgets option to match Twenty Nineteen's zero sidebars.
• Skip some unit tests that depend on current theme's sidebars.

When searching for seventeen, I've also found the DocBlock for WP_Theme_Install_List_Table::single_row()​. Since ​http://2019.wordpress.net/ does not exist, I guess we can leave that one as is for now?

[pento]

45152.2.diff​ looks good, I agree about leaving the DocBlock for WP_Theme_Install_List_Table::single_row() for now.

[pento]

Twenty Nineteen has added a widget area.

[pento]

Converting to a task, this can happen during RC.

[pento]

@karmatosed, @melchoyce: Is there likely to be a 2019.wordpress.net site created?

[karmatosed]

@pento let me loop in @kjellr on this regarding the demo site.

[kjellr]

Is there likely to be a 2019.wordpress.net site created?

@pento Yes! It's in progress at the moment, but the URL will be 2019.wordpress.net. 👍

[pento]

In 45152.3.diff​:

• The nav menu help text is updated to refer to Twenty Nineteen. (This isn't a translatable string change.)
• Update the docblock for WP_Theme_Install_List_Table::single_row() to refer to Twenty Nineteen.

[pento]

In 45152.5.diff​:

Update sidebars_widgets to match Twenty Nineteen's single widget area, and update the customizer tests to match.

[mcsf]

In 43954:

Update sidebars_widgets to match Twenty Nineteen's single widget area

• Also update the customizer tests to match it.

Props SergeyBiryukov, pento.

[pento]

In 44151:

Bundled Themes: Make twentynineteen the default theme.

After [44149], we can now make twentynineteen the default theme. Twentyseventeen has been a great default, but 5.0 and twentynineteen is guten.

Merges [43809,43954] from the 5.0 branch to trunk.

Fixes #45152.
Props jorbin, SergeyBiryukov, pento, mcsf.