This module provides the ability to use a _theme
key in route definitions to specify a theme hook that should be called to return the content for the route.
In your *.routing.yml file:
pages.foo:
path: '/pages/foo'
defaults:
_theme: 'pages_foo'
_title: 'Foo Page'
requirements:
_access: 'TRUE'
This would return a render array for the content of /pages/foo
of:
array('#theme' => 'pages_foo')
There is no configuration other than enabling/disabling the module.