Add alt code to 1991/ant and format README.md

The alt code will make it a bit less unwieldy for vi(m) users by
changing the following input keys to be like in vi(m):

- Use 0 to go to first column.
- Use $ to go to last column.
- Hit ESC to go back to command mode (instead of form-feed, ctrl-L).
- Use w to go forwards one word.
- Use b to go backwards one word.
- Use q to exit.

The rest of the keys were left unchanged.

Format fix README.md file.

This completes 1991/ant checks unless I'm very much mistaken.

1991/ant/Makefile

@@ -116,8 +116,8 @@ OBJ= ${PROG}.o
 DATA= README.md
 TARGET= ${PROG} hill mole
 #
-ALT_OBJ=
-ALT_TARGET=
+ALT_OBJ= ${PROG}.alt.o
+ALT_TARGET= ${PROG}.alt
 
 
 #################