Added some Ch 4 programs + anti-confusion guide
Revert "Added some Ch 4 programs + anti-confusion guide"

This reverts commit 021e40e21ce5d83b3657a5764e5238a60fa3f367.
Revert "Revert "Added some Ch 4 programs + anti-confusion guide""

This reverts commit cd0c985e7cc478659019cba6112806803c51574f.
Updated readme.md