Update README.md (#7214)
Update README.md (#7214)

if you don't grant select on pg_stat_database you only get about 15-19 metrics. most of which are not useful
DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core