Improve 2019/karns/try.sh, force -O0

The try.sh script now prompts for input rather than just sleep for 2
seconds.

The README.md file has been format/typo checked.

Added issues reported by the author to bugs.md.

Force disable optimiser as the program doesn't work in some cases with
it enabled. If I recall correctly it crashed in some cases, something
the author noted happens sometimes (it is unknown if it is because they
had it enabled or if it was something else but I have not experienced a
crash since then).

2019/karns/Makefile

@@ -68,7 +68,8 @@ CINCLUDE=
 
 # Optimization
 #
-OPT=
+# We disable the optimiser because the entry has problems with it enabled.
+OPT= -O0
 
 # Default flags for ANSI C compilation
 #
@@ -137,8 +138,11 @@ all: data ${TARGET}
 	clean clobber install love haste waste maker easter_egg \
 	sandwich supernova deep_magic magic charon pluto
 
+
+# We FORCE the use of -O0 even if someone overrides it because this entry has
+# problems with it enabled.
 ${PROG}: ${PROG}.c
-	${CC} ${CFLAGS} $< -o $@ ${LDFLAGS}
+	${CC} ${CFLAGS} -O0 $< -o $@ ${LDFLAGS}
 	${LN} -sf ${PROG} tbfs
 
 test: ${PROG}