Release notes should display release date

[ajtowns]

The release notes pages are great (eg 28.2 except that they don't include the release date. Some older pages on bitcoin.org do, eg 0.21.0, for comparison, though not recent ones. The markdown files do include a date, so I guess this just isn't being exposed via the layout logic that marks up releases as pages:

bitcoincore.org/_config.yml

Lines 51 to 57 in 07ca5bf

	- scope:
	path: ""
	type: releases
	values:
	type: releases
	layout: page
	lang: en

The post.html layout exposes date information I think:

bitcoincore.org/_layouts/post.html

Lines 52 to 64 in 07ca5bf

	<footer role="contentinfo">
	<p class="byline">
	<strong>{{ page.title }}</strong>
	was published on
	<time class="dt-published" datetime="{{ page.date | date_to_xmlschema }}">
	{{ page.date | date: "%B %d, %Y" }}
	</time>
	{% if page.modified %} and last modified on
	<time datetime="{{ page.modified | date: "%Y-%m-%d" }}">
	{{ page.modified | date: "%B %d, %Y" }}
	</time>{% endif %}.
	</p>
	</footer>

Perhaps something similar could just be added to page.html? Or, maybe a custom layout for releases would make sense?

[fanquake]

Tried something simple in #1160.