Update maintainer list

[skip ci]

libs/maintainers.txt

@@ -40,6 +40,7 @@ coroutine             Oliver Kowalke <oliver.kowalke -at- gmail.com>
 coroutine2            Oliver Kowalke <oliver.kowalke -at- gmail.com>
 crc                   Daryle Walker <darylew -at- hotmail.com>
 date_time             Jeff Garland <jeff -at- crystalclearsoftware.com>, James E. King III <jking -at- apache.org>
+describe              Peter Dimov <pdimov -at- gmail.com>
 detail                Robert Ramey <ramey -at- rrsd.com>, Rene Rivera <grafikrobot -at- gmail.com>, Andrey Semashev <andrey.semashev -at- gmail.com>
 disjoint_sets         Jeremy Siek <jeremy.siek -at- gmail.com>
 dll                   Antony Polukhin <antoshkka -at- gmail.com>
@@ -79,6 +80,7 @@ iterator              David Abrahams <dave -at- boost-consulting.com>, Thomas Wi
 iterator_facade       Zach Laine <whatwasthataddress -at- gmail.com>
 json                  Vinnie Falco <vinnie.falco@gmail.com>
 lambda                Jaakko Jarvi <jarvi -at- cs.tamu.edu>
+lambda2               Peter Dimov <pdimov -at- gmail.com>
 leaf                  Emil Dotchevski
 lexical_cast          Antony Polukhin <antoshkka -at- gmail.com>
 local_function        Lorenzo Caminiti <lorcaminiti -at- gmail.com>