Add @clyang82 as a maintainer of the operator

[clyang82]

This project is not being actively developed in last half year. But we forked this repo in https://github.com/open-cluster-management/observatorium-operator which is being actively developed. we still have more requirements around this operator.

I would like to propose myself to be a maintainer of this operator so that I can fully work on this operator and maintain this repo.

Any comments? @bwplotka @squat @matej-g