More fixes in 1980s README.md files

Where there is not a direct post when referring to a USENET group (for
results etc.) it is no longer a link to the group itself but just made
italic. That means only 1984 has it and only for the contest
announcement.

In 1989 the point about the Makefiles for fubar and tromp have been
clarified a bit. They were ambiguous before: it could have been read as
the Makefile for ALL entries but it was only for that entry. Also since
these points are about the Makefile (and in particular portability of
the original or alt versions) I moved the paragraph to right under the
part about running make to compile (this part has some additional fixes
that will be applied later on).

The years: 1984, 1985, 1986, 1987 and 1989 were updated. There was
nothing to do (for this commit) for 1988 but there is a change that will
be made after discussion.

1989/README.md

@@ -8,21 +8,22 @@ You may then wish to look at the Author's remarks 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 changed).
 
+The Makefile for ["Best self modifying program"](fubar/indx.html) always uses
+the most portable version because there is no loss of functionality in
+using it.  In the case of the ["Best game"](tromp/README) entry, however, some
+functionality is lost in the portable version and so its Makefile uses
+the original program.
+
 This year, the [Best of Show](jar.2/index.html) was given to the most useful program.
 
 The ["Strangest abuse of the rules"](jar.1/indx.html) award was given this year
 to stress the fact that starting in 1990, compiling entries must result a
 regular executable file.
 
-The Makefile always uses the portable version of the ["Best
-self modifying program"](fubar/indx.html) because there is no loss of functionality in
-using it.  In the case of the ["Best game"](tromp/README) entry, however, some
-functionality is lost in the portable version and so the Makefile uses
-the original program.
-
-[Rules](rules.txt) and [results](../years.html#1989) 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 winning entries will be published in the
+[Rules](rules.txt) and [results](../years.html#1989) 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 winning entries will be published in the
 [Micro/Systems
 Journal](https://www.vintage-computer.com/publications.php?microsystemsjournal).