Add options to ignore comments and discards

[frankitox]

Hi 👋!

I have a feature request regarding macro comments and the discard macro reader. I would like to format those and found a TODO comment in the codebase:

cljstyle/src/cljstyle/format/zloc.clj

Lines 126 to 132 in 14c18e5

	(defn ignored-form?
	"True if the node at this location is an ignored form."
	[zloc]
	;; TODO: option for ignoring comments and discards?
	(or (ignore-meta? zloc)
	(comment-form? zloc)
	(discard-macro? zloc)))

I wrote a couple of lines to address it in a fork. Would you be interested in merging something like this? I'll write tests, docs and take any feedback you have about it (I'm not even sure if the approach I chose is any good!).