for TFD, add option to delete all subpages, and default it to "on" (mainly to delete /sandbox /doc /testcases)

[NovemLinguae]

Requested by Izno and Primefac at https://en.wikipedia.org/wiki/Wikipedia_talk:XFDcloser#Feature_request:_Delete_TFDd_template_subpages

"It would be nice to hit the /sandbox, /doc, and /testcases subpages when a TFD is closed as delete (now, rather than holding), and possibly associated redirects. (Maybe with checkmarks? Not sure.) In almost all my recent deletes there I've had to open the 'subpages' link and then manually G8 the remaining subpages. Izno♂ (talk) 9:47 am, 24 May 2021, Monday (3 years, 19 days ago) (UTC−7)

Seconded. I think this should be a default-on option (since there are very rarely occasions where you wouldn't want to delete the subpages) but it would definitely save some extra clicks. Primefac☉ (talk) 10:09 am, 24 May 2021, Monday (3 years, 19 days ago) (UTC−7)"

"Oh, I'm still tossing stuff around, feeling good about suggesting all subpages now. Vibing, as it were. ~ Izno"