Update README.md (#6635)
Update README.md (#6635)

* Update README.md

added username and password fields to the annotations instance_config section, since we advise creating those in our instructions, and clients will run into authorization errors if those are not included.

* Update rabbitmq/README.md

Co-authored-by: Christine Chen <021c7f81bc4c0e55dbc6c4b2db8d0ea775f269a0@users.noreply.github.com>

Co-authored-by: Christine Chen <021c7f81bc4c0e55dbc6c4b2db8d0ea775f269a0@users.noreply.github.com>
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