feat: Specify context in order to be able to manage several cluster in the same time

[cyrinux]

Hi @MnrGreg,

Thanks for the toy.

A tiny modification to be able to play on different clusters in the same time in a safe way. - I understand we actually have to enable the good context with kubectx for example, but if I switch the context while the script is running in the background, this can be dangerous. I let the parameter optional.

If you accept those modifications, can you do a release then ?

Thanks 🙏

[MnrGreg]

thanks for contributing @cyrinux