Co-authored-by: Josh Soref <jsoref@users.noreply.github.com>

The direct assignment of a local array is not possible in older ZSH version, as used by RHEL/CentOS 7.

Also moving the dependencies section up

Fix some comments and messages. Remove (probably) debug messages. Improve ZSH_COLORIZE_TOOL recognition.

cless is an alias for a colorized less wrappper: colorize_via_pygmentize_less.
Note that cless opens many files as independent files, navigatable with `:n` and `:p`.

The option (`pygmentize -f terminal <...>`) lets pygments use terminal color
scheme. Otherwise, it would use its default colors, which might be
unbalanced with that of terminal (e.g. not harmonious with background color of terminal).

correctly detect when pygmentize is not installed
do not exit shell if when pygmentize is not installed