debian: Rework installed documentation

debian/changelog

@@ -86,6 +86,8 @@ dpkg (1.18.0) UNRELEASED; urgency=low
     - Name each public-domain license with a different name.
     - Add missing public modules to dpkg-dev package description.
     - Get rid of backward compatibility pseudo-tags from bug reports.
+    - Install doc/README.feature-removal-schedule only on affected packages
+      and debian/usertags everywhere.
   * Documentation:
     - Document arch-qualifiers for dependency fields in deb-control(5) and
       deb-src-control(5). Reported by Johannes Schauer <j.schauer@email.de>.

debian/dselect.docs

@@ -1,5 +1,4 @@
 AUTHORS
 THANKS
 debian/usertags
-doc/README.feature-removal-schedule
 dselect/methods/multicd/README.multicd

debian/libdpkg-dev.docs

@@ -2,4 +2,3 @@ AUTHORS
 THANKS
 debian/usertags
 doc/README.api
-doc/README.feature-removal-schedule

debian/libdpkg-perl.docs

@@ -1,4 +1,5 @@
 AUTHORS
 THANKS
+debian/usertags
 doc/README.api
 doc/README.feature-removal-schedule