Add tsearch2 mention.
Add tsearch2 mention.

atris/gpdb,snaga/postgres-xl,yazun/postgres-xl,greenplum-db/gpdb,ashwinstar/gpdb,lpetrov-pivotal/gpdb,snaga/postgres-xl,royc1/gpdb,royc1/gpdb,ahachete/gpdb,xinzweb/gpdb,Quikling/gpdb,atris/gpdb,zaksoup/gpdb,ovr/postgres-xl,kaknikhil/gpdb,lisakowen/gpdb,arcivanov/postgres-xl,lpetrov-pivotal/gpdb,ashwinstar/gpdb,adam8157/gpdb,yuanzhao/gpdb,kaknikhil/gpdb,zaksoup/gpdb,pavanvd/postgres-xl,pavanvd/postgres-xl,zeroae/postgres-xl,adam8157/gpdb,janebeckman/gpdb,xuegang/gpdb,janebeckman/gpdb,adam8157/gpdb,lisakowen/gpdb,cjcjameson/gpdb,postmind-net/postgres-xl,xuegang/gpdb,chrishajas/gpdb,atris/gpdb,xinzweb/gpdb,Chibin/gpdb,lisakowen/gpdb,0x0FFF/gpdb,royc1/gpdb,arcivanov/postgres-xl,Quikling/gpdb,janebeckman/gpdb,xinzweb/gpdb,techdragon/Postgres-XL,0x0FFF/gpdb,pavanvd/postgres-xl,edespino/gpdb,kmjungersen/PostgresXL,techdragon/Postgres-XL,janebeckman/gpdb,cjcjameson/gpdb,rubikloud/gpdb,lisakowen/gpdb,xuegang/gpdb,zaksoup/gpdb,ashwinstar/gpdb,CraigHarris/gpdb,foyzur/gpdb,chrishajas/gpdb,xinzweb/gpdb,jmcatamney/gpdb,snaga/postgres-xl,tpostgres-projects/tPostgres,ashwinstar/gpdb,lpetrov-pivotal/gpdb,rvs/gpdb,edespino/gpdb,lintzc/gpdb,pavanvd/postgres-xl,50wu/gpdb,greenplum-db/gpdb,randomtask1155/gpdb,lintzc/gpdb,jmcatamney/gpdb,zaksoup/gpdb,rubikloud/gpdb,xuegang/gpdb,kaknikhil/gpdb,Quikling/gpdb,arcivanov/postgres-xl,Chibin/gpdb,edespino/gpdb,snaga/postgres-xl,cjcjameson/gpdb,kaknikhil/gpdb,jmcatamney/gpdb,kaknikhil/gpdb,xuegang/gpdb,adam8157/gpdb,lintzc/gpdb,janebeckman/gpdb,rubikloud/gpdb,50wu/gpdb,edespino/gpdb,kaknikhil/gpdb,techdragon/Postgres-XL,yuanzhao/gpdb,edespino/gpdb,rvs/gpdb,tpostgres-projects/tPostgres,edespino/gpdb,Chibin/gpdb,foyzur/gpdb,0x0FFF/gpdb,atris/gpdb,lintzc/gpdb,edespino/gpdb,ahachete/gpdb,cjcjameson/gpdb,ashwinstar/gpdb,randomtask1155/gpdb,chrishajas/gpdb,kaknikhil/gpdb,royc1/gpdb,randomtask1155/gpdb,royc1/gpdb,CraigHarris/gpdb,50wu/gpdb,xuegang/gpdb,Quikling/gpdb,Chibin/gpdb,rvs/gpdb,ahachete/gpdb,oberstet/postgres-xl,greenplum-db/gpdb,ovr/postgres-xl,lintzc/gpdb,CraigHarris/gpdb,Chibin/gpdb,randomtask1155/gpdb,jmcatamney/gpdb,50wu/gpdb,ahachete/gpdb,tangp3/gpdb,zaksoup/gpdb,janebeckman/gpdb,tpostgres-projects/tPostgres,ahachete/gpdb,atris/gpdb,CraigHarris/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,rvs/gpdb,tangp3/gpdb,tpostgres-projects/tPostgres,tpostgres-projects/tPostgres,lintzc/gpdb,royc1/gpdb,foyzur/gpdb,yazun/postgres-xl,xinzweb/gpdb,zaksoup/gpdb,tangp3/gpdb,Postgres-XL/Postgres-XL,cjcjameson/gpdb,xinzweb/gpdb,50wu/gpdb,rvs/gpdb,ovr/postgres-xl,rubikloud/gpdb,adam8157/gpdb,jmcatamney/gpdb,0x0FFF/gpdb,yuanzhao/gpdb,arcivanov/postgres-xl,xuegang/gpdb,chrishajas/gpdb,lintzc/gpdb,Quikling/gpdb,rubikloud/gpdb,oberstet/postgres-xl,rubikloud/gpdb,rvs/gpdb,CraigHarris/gpdb,oberstet/postgres-xl,lpetrov-pivotal/gpdb,pavanvd/postgres-xl,edespino/gpdb,atris/gpdb,kmjungersen/PostgresXL,ashwinstar/gpdb,cjcjameson/gpdb,adam8157/gpdb,royc1/gpdb,lisakowen/gpdb,Quikling/gpdb,foyzur/gpdb,Quikling/gpdb,cjcjameson/gpdb,greenplum-db/gpdb,rubikloud/gpdb,kaknikhil/gpdb,xinzweb/gpdb,0x0FFF/gpdb,jmcatamney/gpdb,kmjungersen/PostgresXL,atris/gpdb,foyzur/gpdb,arcivanov/postgres-xl,foyzur/gpdb,lpetrov-pivotal/gpdb,chrishajas/gpdb,foyzur/gpdb,adam8157/gpdb,zaksoup/gpdb,tangp3/gpdb,lisakowen/gpdb,janebeckman/gpdb,techdragon/Postgres-XL,0x0FFF/gpdb,Quikling/gpdb,jmcatamney/gpdb,randomtask1155/gpdb,janebeckman/gpdb,chrishajas/gpdb,rvs/gpdb,yazun/postgres-xl,arcivanov/postgres-xl,yazun/postgres-xl,royc1/gpdb,zaksoup/gpdb,0x0FFF/gpdb,0x0FFF/gpdb,ovr/postgres-xl,tangp3/gpdb,greenplum-db/gpdb,ovr/postgres-xl,greenplum-db/gpdb,rvs/gpdb,CraigHarris/gpdb,kmjungersen/PostgresXL,xuegang/gpdb,lpetrov-pivotal/gpdb,randomtask1155/gpdb,lintzc/gpdb,ashwinstar/gpdb,ahachete/gpdb,lpetrov-pivotal/gpdb,xinzweb/gpdb,Postgres-XL/Postgres-XL,yazun/postgres-xl,50wu/gpdb,techdragon/Postgres-XL,oberstet/postgres-xl,foyzur/gpdb,rubikloud/gpdb,tangp3/gpdb,Quikling/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,Quikling/gpdb,Chibin/gpdb,zeroae/postgres-xl,ashwinstar/gpdb,postmind-net/postgres-xl,snaga/postgres-xl,50wu/gpdb,50wu/gpdb,greenplum-db/gpdb,CraigHarris/gpdb,rvs/gpdb,yuanzhao/gpdb,greenplum-db/gpdb,lintzc/gpdb,janebeckman/gpdb,tangp3/gpdb,zeroae/postgres-xl,randomtask1155/gpdb,CraigHarris/gpdb,Chibin/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,atris/gpdb,ahachete/gpdb,janebeckman/gpdb,edespino/gpdb,chrishajas/gpdb,ahachete/gpdb,kmjungersen/PostgresXL,cjcjameson/gpdb,Postgres-XL/Postgres-XL,zeroae/postgres-xl,zeroae/postgres-xl,lisakowen/gpdb,yuanzhao/gpdb,edespino/gpdb,xuegang/gpdb,Postgres-XL/Postgres-XL,Postgres-XL/Postgres-XL,oberstet/postgres-xl,CraigHarris/gpdb,Chibin/gpdb,kaknikhil/gpdb,adam8157/gpdb,Chibin/gpdb,tangp3/gpdb,randomtask1155/gpdb,jmcatamney/gpdb,postmind-net/postgres-xl,rvs/gpdb,lpetrov-pivotal/gpdb,postmind-net/postgres-xl,chrishajas/gpdb,postmind-net/postgres-xl,kaknikhil/gpdb,cjcjameson/gpdb,Chibin/gpdb,lisakowen/gpdb