Previously the alt rule in the Makefile defined NO_STTY which stops the
code from using stty(1) at the beginning and at the end. The stty sane
resulted in a bus error in macOS and since the sole purpose was to set
echo back on I changed it to stty echo (which works). (The NO_STTY macro
is still checked, see below.)
Added alt code with vi(m) like movements.
The way to get it to not use stty is to use either make alt-no_stty or
no_stty. The former will compile into anon.alt and the latter will
compile into anon.
Format and typo fix README.md file.
