Update 2020/ferguson[12]

Surprise, surprise there are more updates on my entries! :-) But to be
fair to me there were some important fixes and I had not really gone
through the README files of these entries (I still didn't go through all
of them thoroughly and probably won't since I'm far too concise :-)
:-)). In fact some of these problems broke some of the features of some
of the entries.

In 2020/ferguson1: termcaps must be compiled by make all. It also needed
a make test rule that runs ./termcaps. As well it needed a play and
snake-colours rule which copies and chmod +x the respective .sh files.

There were some typo fixes here and there as well as (I hope) a bit
clearer wording.

Some out of date things were changed.

2020/ferguson2/Makefile

@@ -168,7 +168,7 @@ OBJ= ${PROG}.o
 DATA= chocolate-cake.md enigma.1 input.txt obfuscation.key \
 	obfuscation.md obfuscation.txt recode.1 recode.md \
 	try.this.txt
-TARGET= ${PROG}
+TARGET= ${PROG} recode
 #
 ALT_OBJ=
 ALT_TARGET=
@@ -188,6 +188,9 @@ all: data ${TARGET}
 ${PROG}: ${PROG}.c
 	${CC} ${CFLAGS} $< -o $@ ${LIBS}
 
+recode: recode.c
+	${CC} ${CFLAGS} $< -o $@ ${LIBS}
+
 # alternative executable
 #
 alt: data ${ALT_TARGET}