Add <cite> to endnotes

src/epub/text/endnotes.xhtml

@@ -10,7 +10,7 @@
 			<h2 epub:type="title">Endnotes</h2>
 			<ol>
 				<li id="note-1" epub:type="endnote">
-					<p>The poem “After-Life” was published in <i epub:type="se:name.publication.magazine">Overland Monthly, <abbr>vol.</abbr> 37, <abbr>no.</abbr> 1</i>, and was not included in the original publication of <i epub:type="se:name.publication.book">The Book of Jade</i>. <a href="after-life.xhtml#noteref-1" epub:type="backlink">↩</a></p>
+					<p>The poem “After-Life” was published in <i epub:type="se:name.publication.magazine">Overland Monthly, <abbr>vol.</abbr> 37, <abbr>no.</abbr> 1</i>, and was not included in the original publication of <i epub:type="se:name.publication.book">The Book of Jade</i>. <cite>—<abbr epub:type="z3998:initialism">S.E.</abbr> Editor</cite> <a href="after-life.xhtml#noteref-1" epub:type="backlink">↩</a></p>
 				</li>
 			</ol>
 		</section>