Update several year README.md files

Mostly added links.

1989/README.md

@@ -7,23 +7,23 @@ Look at the winning source and try to figure how it does what it does!
 You may then wish to look at the Author's comments for even more details.
 
 Instructions for use: Run make to compile entries (it is possible
-that on System V or non-unix systems the makefile needs to be
+that on System V or non-unix systems the Makefile needs to be
 changed).
 
 This year, the Grand Prize was given to the most useful program.
 
-The "Strangest abuse of the rules" award was given this year to stress
-the fact that starting in 1990, compiling entries must result an
+The ["Strangest abuse of the rules"](jar.1/README.md) award was given this year
+to stress the fact that starting in 1990, compiling entries must result an
 executable regular file.
 
-The makefile always uses the portable version of the "Best
-self modifying program" because there as no loss of functionality in
-using it.  In the case of the "Best game" winner, however, some
-functionality is lost in the portable version and so the makefile uses
-the original program.  System V users may need to change the makefile
+The Makefile always uses the portable version of the ["Best
+self modifying program"](fubar/) because there as no loss of functionality in
+using it.  In the case of the ["Best game"](tromp/) winner, however, some
+functionality is lost in the portable version and so the Makefile uses
+the original program.  System V users may need to change the Makefile
 to use the s5 version.  See the hint files or the Makefile for details.
 
-Rules and results were posted to comp.lang.c, comp.sources.unix, and
+[Rules](rules.txt) and results were posted to comp.lang.c, comp.sources.unix, and
 alt.sources.  They have been made available on a wide number of Usenet
 archive sites such as uunet.  The 1989 winners will be published in the
 Micro/Systems Journal.