Importing needs to be manipulated by script. But it's too verbose to use
script always.
If link tag can be inserted in body tag, and inserts importee's
document.body to importer, then it would be easily without any scripts.
An example is below:
component.html:
!DOCTYPE html
div
p
The current spec says that the internal worker scope is
WorkerGlobalScope(or Dedi-, Shared-), the external is AbstractWorker(or
Worker, Shared-.) But it destroys consistency with Window object and
confuses users with the difference of WorkerGlobalScope and AbstractWorker.
The global scope
It would be good to restrict custom element's name to start with like
'x-' for the future standards. User-defined custom attributes; data
attributes are also restricted its name to start with 'data-' so we can
define easily new standard attribute names ('aria-*' or everything
except for
