note vector lib lead in authors file

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@64724 15284696-431f-4ddb-bdfa-cd5b030d7da7

AUTHORS

@@ -50,7 +50,8 @@ GRASS 7.0 major project contributers
 
 LEAD ARCHITECT
  - Glynn Clements <glynn at gclements plus com>
-
+ - Markus Metz <markus.metz.giswork gmail.com>: Vector library lead
+ 
 GUI
  - Martin Landa <landa.martin gmail com>: wxPython GUI lead