doc: Fix typos
doc: Fix typos

From: Erik Rijkers <602c57ffb51af99d6f3b54c0ee9587bb110fb990@xs4all.nl>

xinzweb/gpdb,adam8157/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,lisakowen/gpdb,lisakowen/gpdb,adam8157/gpdb,lisakowen/gpdb,jmcatamney/gpdb,50wu/gpdb,50wu/gpdb,lisakowen/gpdb,50wu/gpdb,greenplum-db/gpdb,50wu/gpdb,50wu/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,lisakowen/gpdb,greenplum-db/gpdb,adam8157/gpdb,ashwinstar/gpdb,50wu/gpdb,lisakowen/gpdb,xinzweb/gpdb,adam8157/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,xinzweb/gpdb,lisakowen/gpdb,xinzweb/gpdb,ashwinstar/gpdb,xinzweb/gpdb,xinzweb/gpdb,xinzweb/gpdb,adam8157/gpdb,greenplum-db/gpdb,50wu/gpdb,50wu/gpdb,xinzweb/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,adam8157/gpdb,adam8157/gpdb,adam8157/gpdb,jmcatamney/gpdb,lisakowen/gpdb,ashwinstar/gpdb,greenplum-db/gpdb