refresh for v3?

[fopina]

Could this plugin be updated to reflect v3?

Or is there another official example?

Or should stdout from main repository be used as example?
Those miss the CMakeFile templates and such

[fopina]

For anyone going through here, this root CMakeLists.txt plus out_stdout from main repo (https://github.com/fluent/fluent-bit/tree/v3.1.9/plugins/out_stdout) work well

It would be nice this root CMakeLists.txt maintained somewhere though