Equivalent to the Changelog method with a preset regex for debian/changelog files.

• This is really just a variation of plain changelogs.
  
  Uses the same backend code with a regex of:

   /^[\w-]+\h+\((\d[\w.-]+)\)\s*\w+;\s*urgency=\w+\h*$/m;

  And only strips the trailing -- author/date… suffix

• Technically they're package release logs.

• See https://www.debian.org/doc/manuals/maint-guide/dreq.en.html#changelog

   package (0.1.2-3) STATE; urgency=SCOPE
  
     * First package. Closes: #54321
     * As stolen from Gentoo.
     * Introduced arbitrary DFSG constraint.
  
    -- Elisa Examplary <liz@debian.org>  Mon, 25 May 2016 01:22:33 +0100

• Requires the autoupdate_url to the plain changelog file.

• Now state and scope aren't yet mapped.

• Added this reluctantly. But they're still common enough to warrant support.