Remove duplicate badge-printing documentation

Commit 27da8d0 added what's basically a copy of the badge printing
documentation in a different location, so remove the one from the
original location as they had over time gone out of sync.

docs/confreg/badges.md

@@ -7,25 +7,5 @@ CSV list of all registrations and create them separately).
 
 To create badges, use the [Attendee reports](reports#attendee) page.
 
-**Always** create a filter that includes "Payment confirmed". Without
-this, badges would be created for attendees who have not paid. The
-"Payment confirmed" field will be set automatically even for
-registrations that don't need payment, as soon as they are confirmed.
-
-Select output format "badge", and decide if you want borders and/or
-page breaks included, depending on printing requirements and the badge
-design itself.
-
 It doesn't matter which fields are included, as the badge template
 will always have access to all badges.
-
-### Incremental printing
-
-If badges need to be printed incrementally (for example if most badges
-have been printed but late registrations have to be printed as a
-separate batch), use the date filter functionality on *payment
-confirmed*. If the last batch was printed on 2017-10-20 for example,
-enter ">2017-10-20" in the filter field.
-
-For easier validation, generate a normal report with this filter
-first, and change the output format to *Badges* when ready.