MAINTAINERS: Add entry for Sphinx documentation infrastructure

Add a MAINTAINERS entry for Sphinx documentation infrastructure:
this doesn't cover actual content, only the machinery we use to
build the docs.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190305172139.32662-13-peter.maydell@linaro.org
diff --git a/MAINTAINERS b/MAINTAINERS
index 5040d9d..074ad46 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2567,3 +2567,9 @@
 M: Daniel P. Berrange <berrange@redhat.com>
 S: Odd Fixes
 F: scripts/git-submodule.sh
+
+Sphinx documentation configuration and build machinery
+M: Peter Maydell <peter.maydell@linaro.org>
+S: Maintained
+F: docs/conf.py
+F: docs/*/conf.py