docs: README: reflect organization and status change

Signed-off-by: Eduardo Silva <[email protected]>

Author: edsiper

README.md

@@ -133,6 +133,6 @@ Fluent Bit is open to community contributions!
 
 ## Authors
 
-Fluent Bit is a CNCF sub-project, sponsored and maintained by major cloud providers and a growing community of contributors and maintainers from across the Cloud Native ecosystem.
+Fluent Bit is a CNCF graduated project, sponsored and maintained by major cloud providers and a growing community of contributors and maintainers from across the Cloud Native ecosystem.
 
 👉 [See Contributors](https://github.com/fluent/fluent-bit/graphs/contributors)