Sort posts by timestamp in the RSS and Atom feeds
Posts in the per-language feeds seem to be in the correct order, but the global feed is only sorted by date ignoring the time (I think it's sorted by _posts
filename, ie. date + title). For example this is the current RSS feed:
$ grep pubDate _site/global/rss20.xml/index.html
<pubDate>2020-03-16 11:00:00 UTC</pubDate>
<pubDate>2020-03-16 11:40:00 UTC</pubDate>
<pubDate>2020-03-16 06:17:41 UTC</pubDate>
<pubDate>2020-03-15 05:34:40 UTC</pubDate>
<pubDate>2020-03-15 10:01:10 UTC</pubDate>
<pubDate>2020-03-15 10:00:16 UTC</pubDate>
<pubDate>2020-03-15 18:39:00 UTC</pubDate>
<pubDate>2020-03-14 13:15:00 UTC</pubDate>
<pubDate>2020-03-14 11:25:49 UTC</pubDate>
<pubDate>2020-03-14 00:02:55 UTC</pubDate>
This patch explicitly sorts posts by full timestamp before creating the RSS and Atom feeds.