Enhancements for CLI reference documentation

[jvanz]

Try to improve the CLI reference documentation files by removing the weird chars (e.g. right angled down pointing arrows) and generate asciidoc version of the file:

          looks ok. Is that right angled down pointing arrow useful/necessary?

          Also, can asciidoc be generated (in due course). Sorry, should have asked that earlier.

_Originally posted by @jhkrug in #491 (review)

Acceptance criteria

• Consider a upstream contributation to add this features to clap_markdown
• If the upstream contribution is not possible, manipulate the file copied from kwctl repository (and others, if they exists)

[jvanz]

I've opened two issues in the clap_markdown repository to talk about the two changes that we would like to have in the crate:

ConnorGray/clap-markdown#39
ConnorGray/clap-markdown#40

[jvanz]

@jhkrug, how pressure is the asciidoc generation ? Should be priority it or it can wait?