docs: more xml tag cleanup
docs: more xml tag cleanup

janebeckman/gpdb,xinzweb/gpdb,ashwinstar/gpdb,cjcjameson/gpdb,50wu/gpdb,edespino/gpdb,edespino/gpdb,yuanzhao/gpdb,Chibin/gpdb,lisakowen/gpdb,greenplum-db/gpdb,cjcjameson/gpdb,xinzweb/gpdb,greenplum-db/gpdb,janebeckman/gpdb,yuanzhao/gpdb,jmcatamney/gpdb,lisakowen/gpdb,Chibin/gpdb,jmcatamney/gpdb,edespino/gpdb,50wu/gpdb,lisakowen/gpdb,50wu/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,edespino/gpdb,edespino/gpdb,janebeckman/gpdb,Chibin/gpdb,50wu/gpdb,ashwinstar/gpdb,cjcjameson/gpdb,lisakowen/gpdb,xinzweb/gpdb,janebeckman/gpdb,cjcjameson/gpdb,jmcatamney/gpdb,lisakowen/gpdb,edespino/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,adam8157/gpdb,cjcjameson/gpdb,lisakowen/gpdb,ashwinstar/gpdb,adam8157/gpdb,greenplum-db/gpdb,yuanzhao/gpdb,greenplum-db/gpdb,50wu/gpdb,Chibin/gpdb,Chibin/gpdb,edespino/gpdb,janebeckman/gpdb,cjcjameson/gpdb,edespino/gpdb,adam8157/gpdb,xinzweb/gpdb,Chibin/gpdb,jmcatamney/gpdb,janebeckman/gpdb,janebeckman/gpdb,janebeckman/gpdb,cjcjameson/gpdb,janebeckman/gpdb,jmcatamney/gpdb,Chibin/gpdb,greenplum-db/gpdb,50wu/gpdb,adam8157/gpdb,adam8157/gpdb,50wu/gpdb,adam8157/gpdb,jmcatamney/gpdb,cjcjameson/gpdb,50wu/gpdb,edespino/gpdb,lisakowen/gpdb,yuanzhao/gpdb,cjcjameson/gpdb,adam8157/gpdb,jmcatamney/gpdb,yuanzhao/gpdb,edespino/gpdb,xinzweb/gpdb,adam8157/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,janebeckman/gpdb,xinzweb/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,Chibin/gpdb,xinzweb/gpdb,yuanzhao/gpdb,Chibin/gpdb,Chibin/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,cjcjameson/gpdb,ashwinstar/gpdb,lisakowen/gpdb,xinzweb/gpdb