Add doc clarifications for warm standby.
Add doc clarifications for warm standby.

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