Sort the feed in chronological order

.. and make sure all the times are at midnight GMT on the date the board
was added. Before this, the date was printed in the generating local time
zone; adding 12 hours often (but not always) made it be in the same GMT
day.

Author: jepler

feed.html

@@ -8,8 +8,8 @@
 <link>{{ "/" | absolute_url }}</link>
 <description>A list of CircuitPython and Blinka supported boards</description>
 <lastBuildDate>{{ "now" | date_to_rfc822 }}</lastBuildDate>
-{% assign chronological_boards = site.board | sort: "date_added" %}
-{% for board in chronological_boards reversed %}
+{% assign all_boards = site.board | concat: site.blinka | sort: "date_added" | reverse %}
+{% for board in all_boards %}
   {%- if board.downloads_display == false -%}
     {%- continue -%}
   {%- endif -%}
@@ -18,20 +18,13 @@
     <title>{{ board.name }}</title>
     <link>{{ board.url | absolute_url }}</link>
     <description><![CDATA[ {% include downloads/board_image.html board_image=board.board_image %}<p>By {{ board.manufacturer }}</p> {{ board.content }} ]]></description>
+    {% if board.blinka %}
+    <category>Blinka</category>
+    {% else %}
     <category>CircuitPython</category>
-    <pubDate>{{ board.date_added | date: '%s' | plus: twelve_hours | date_to_rfc822 }}</pubDate>
+    {% endif %}
+    <pubDate>{{ board.date_added | date: "%a, %d %b %Y 00:00:00 GMT" }}</pubDate>
     <guid>{{ board.url | absolute_url }}</guid>
   </item>
   {%- endif -%}
 {% endfor %}
-{% assign chronological_blinka_boards = site.board | sort: "date_added" %}
-{% for board in chronological_blinka_boards reversed %}
-    <item>
-      <title>{{ board.name }}</title>
-      <link>{{ board.url | absolute_url }}</link>
-      <description><![CDATA[ {% include downloads/board_image.html board_image=board.board_image %}<p>By {{ board.manufacturer }}</p> {{ board.content }} ]]></description>
-      <category>Blinka</category>
-      <pubDate>{{ board.date_added | date: '%s' | plus: twelve_hours | date_to_rfc822 }}</pubDate>
-      <guid>{{ board.url | absolute_url }}</guid>
-    </item>
-{% endfor %}