Add series order metadata

src/epub/content.opf

@@ -37,7 +37,8 @@
 		<meta property="term" refines="#subject-2">sh2009125313</meta>
 		<meta property="se:subject">Science Fiction</meta>
 		<meta property="belongs-to-collection" id="collection-1">Arcot, Morey, and Wade</meta>
-		<meta property="collection-type" refines="#collection-1">series</meta>
+		<meta property="collection-type" refines="#collection-1">set</meta>
+		<meta property="group-position" refines="#collection-1">2</meta>
 		<dc:description id="description">Four men become the first humans to travel to other galaxies.</dc:description>
 		<meta id="long-description" property="se:long-description" refines="#description">
 			&lt;p&gt;Though better known as the editor for authors such as Isaac Asimov and Robert Heinlein, &lt;a href="https://standardebooks.org/ebooks/john-w-campbell"&gt;John &lt;abbr&gt;W.&lt;/abbr&gt; Campbell&lt;/a&gt; also wrote science fiction under both his own and various pen names. &lt;i&gt;Islands of Space&lt;/i&gt; was the second in his &lt;a href="https://standardebooks.org/collections/arcot-morey-and-wade"&gt;Arcot, Morey, and Wade&lt;/a&gt; trilogy. Originally published in the spring 1931 edition of &lt;i&gt;Amazing Stories Quarterly&lt;/i&gt;, it was later published in book form in 1957.&lt;/p&gt;