.zshrc: Fix arrow key issues after launching "top"
.zshrc: Turn off keypad transmit mode

Keypad transmit mode, which changes the control sequences produced by
arrow keys and keypad keys, consists of "application cursor key mode"
and "application keypad key mode".

Some commands like "top" sets this mode, but does not clear it when they
exit. So, the line editor (ZLE) should clear the keypad transmit mode
when it starts.
.zshrc: Use completers only when attempted twice