app-text/sigil: Add proxy-maintainer information

Signed-off-by: Zamarin Arthur <arthurzam@gmail.com>

app-text/sigil/metadata.xml

@@ -1,7 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
 <pkgmetadata>
-<!-- maintainer-needed -->
+	<maintainer type="person">
+		<email>arthurzam+gentoo@gmail.com</email>
+		<name>Arthur Zamarin</name>
+	</maintainer>
+	<maintainer type="project">
+		<email>proxy-maint@gentoo.org</email>
+		<name>Proxy Maintainers</name>
+	</maintainer>
 	<longdescription lang="en">Sigil is a multi-platform WYSIWYG ebook editor.
 		It is designed to edit books in ePub format.</longdescription>
 	<upstream>