New defcustom org-hugo-goldmark (default = t)

[kaushalmodi]

Hello all,

I introduced a new defcustom org-hugo-goldmark in #484.

This variable defaults to t.

If you are using Hugo v0.60.0 or newer (which is very likely as that version was released 2 years back, this variable should be kept at its default value of t.

What this variable does

This variable is meant to gradually undo all the hacks that were put in ox-hugo to support some issues in the old markdown parser that Hugo was using (Blackfriday).

1. Multi line footnotes #484 undoes the multi-line footnote hack.
2. Don't replace _ in links with %5f if using Goldmark #494 prevents the now-unnecessary replacing of _ with %5f in URLs.
3. Remove extra divs #496 removes the <div></div> hack.
4. Src/Example blocks use code fence instead of highlight if Goldmark #499 uses code fences instead of the highlight shortcode for src and example blocks
5. Remove Blackfriday extension support if org-hugo-goldmark #531 removes support of HUGO_BLACKFRIDAY keyword
6. Pass html attr using code block attr #571 passes HTML attributes to code blocks in the curly braces after the code fences