Include po/README in the source tarball

Makefile.in.in ignores EXTRA_DIST.

Makefile.am

@@ -14,6 +14,7 @@ dist_doc_DATA = AUTHORS ChangeLog COPYING LICENSE NEWS PROBLEMS PROJECTS \
  README.zeta
 EXTRA_DIST = $(PACKAGE).lsm
 EXTRA_DIST += .editorconfig
+EXTRA_DIST += po/README
 
 #
 # Keep the .gitignore files sorted, and use this target to do it.

po/Makevars

@@ -47,6 +47,3 @@ width_options     = --width=75
 #  Locale categories, in addition to LC_MESSAGES, for which message
 #  catalogs are to be used.
 EXTRA_LOCALE_CATEGORIES =
-
-EXTRA_DIST  = README
-EXTRA_DIST += Rules-automake