1. Correct a missing reference in Makefile.
2. Correct some typos and other grammatical issues with README.mk-devel.
diff --git a/Makefile b/Makefile
index b215b79..0968409 100644
--- a/Makefile
+++ b/Makefile
@@ -31,8 +31,7 @@
include $(top_srcdir)/include/mk/automake.mk
# This variable is automatically changed from help to all once someone has
-# run configure, or the equivalent steps manually, as described in
-# README.mk-user.
+# run configure, or the equivalent steps manually, as described in INSTALL.
ifeq ($(wildcard $(top_builddir)/include/config.h),)
.DEFAULT_GOAL := help
else