BUG: Staticman reply to functionality broken

[VincentTam]

Bug Report

Describe the bug

d167a64#diff-85c25c44f14e0dffc5bd8fd39626dd2cceca217246cc929cf060eb3fe6541c13 in #154 commented out the line for getting the reply thread ID ("oldest ancestor ID").

hugo-future-imperfect-slim/layouts/_default/comments.html

Lines 81 to 89 in d167a64

	<a class="comment-date" href="#{{ ._id }}" title="Permalink to this comment">
	<time datetime="{{ .date }}">{{ dateFormat "02 Jan 06 15:04" .date }}</time>
	</a>
	</div>
	<!-- TODO: Assess Value (ref ln#73): <a href='#{{ .replyID }}' class='reply-target'>{{ .replyName }}</a> -->
	<!-- TODO: Assess Value: <span class ="comment-threadID hidden">{{ .replyThread }}</span> -->
	<a class="comment-reply-btn" href="#say-something">{{ i18n "reply" }}</a>
	</div>
	</header>

That gives empty fields[replyThread] b/c the element <span class="comment-threadID"> isn't there.

hugo-future-imperfect-slim/assets/js/staticman.js

Lines 81 to 83 in d167a64

	var replyThread = cmt.find('.comment-threadID').text();
	$('.new-comment input[name="fields[replyThread]"]').val(replyThread);
	$('.new-comment input[name="fields[replyID]"]').val(cmt.attr("id"));

Expected behavior

When the reply button is clicked, the reply target's {{ .replyThread }} ("oldest ancestor ID") is copied to fields[replyThread].

Additional context

• nested comment support: Staticman nested comments support from Huginn #69
• my blog post about nested comment: https://vincenttam.gitlab.io/post/2019-07-30-more-static-nested-comments/