yaml configuration is production ready (#1201)

Signed-off-by: Enderson Maia <[email protected]>

Author: endersonmaia

administration/configuring-fluent-bit/README.md

@@ -3,7 +3,7 @@
 Currently, Fluent Bit supports two configuration formats:
 
 * [Classic mode](classic-mode/README.md).
-* [Yaml](yaml/README.md). (YAML configuration is tech preview so not recommended for production.)
+* [Yaml](yaml/README.md). (YAML configuration is production ready since Fluent Bit 2.0.)
 
 ## CLI flags