doc: drop README symlinks, not needed

GitHub supports index.md as an alternative name, which fits better with
what we use with MkDocs.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

doc/config/Makefile.am

@@ -1,7 +1,6 @@
-configdocsdir   := @docdir@/doc/config
-configdocs_DATA  = README.md cgroups.md env.md files.md index.md	\
-		   limitations.md logging.md rescue.md runlevels.md	\
-		   runparts.md service-env.md service-opts.md		\
-		   service-sync.md service-wrappers.md services.md	\
-		   sysv.md task-and-run.md templating.md tty.md
-EXTRA_DIST = $(configdocs_DATA)
+docsdir        := @docdir@/doc/config
+dist_docs_DATA  = cgroups.md env.md files.md index.md limitations.md	\
+		  logging.md rescue.md runlevels.md runparts.md 	\
+		  service-env.md service-opts.md service-sync.md	\
+		  service-wrappers.md services.md sysv.md		\
+		  task-and-run.md templating.md tty.md

doc/config/README.md

@@ -1 +0,0 @@
-index.md