gnome-extra/gtkhtml: take over maintenance

gtkhtml is deprecated and our Gnome project would like to get rid of it,
unfortunately without it app-text/xiphos has to be built without editor
support (which is the way e.g. Debian, Ubuntu and Red Hat have gone) and
from what I have seen many people are unhappy about the inability to use
the Studypad or make personal annotations. Xiphos is now the only
remaining consumer of this library so I shall maintain it between now
and until upstream have implemented a working alternative (apparently
they began to discuss it back in April), after which it will be
last-rited.

Discussed with and approved by leio on IRC.

Bug: https://bugs.gentoo.org/667914
Signed-off-by: Marek Szuba <[email protected]>

gnome-extra/gtkhtml/metadata.xml

@@ -1,8 +1,16 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
 <pkgmetadata>
-<maintainer type="project">
-	<email>gnome@gentoo.org</email>
-	<name>Gentoo GNOME Desktop</name>
+<maintainer type="person">
+	<email>marecki@gentoo.org</email>
+	<name>Marek Szuba</name>
 </maintainer>
+<longdescription>
+	This is the old, and by now very much deprecated, Gtk+ HTML engine. It remains
+	available in Gentoo because as of late July 2020 <pkg>app-text/xiphos</pkg>
+	continues to rely on it for editor functionality (the alternative, WebKit-based
+	editor is not compatible with <pkg>net-libs/webkit-gtk</pkg>:4), however
+	it will be removed as soon as Xiphos upstream has implemented an alternative
+	solution.
+</longdescription>
 </pkgmetadata>