Remove Katacoda references

[usrGabriel]

Since the Katacoda service shut down in May (https://www.oreilly.com/online-learning/leveraging-katacoda-technology.html), the online interactive environment is no longer available. Removed references to it in the project to avoid having dead links for now.

Also kept the Kubernetes docs Katacoda reference since they kept the K8s tutorials scenarios online.

A possible alternative could be KillerCoda (made by the authors of Killer.sh)

[madhuakula]

Hi @usrGabriel

First of all, thank you so much for the update and PR 🎉

Yes, I am aware of this change of Katacoda with O'Reilly and also with Killer code and others.

But I am working on something more user-specific so they don't bind to any of these platforms otherwise they end up having issues later when they change policies.

For now, I will merge the PR. I am working on easy to try in-browser experience using the user's own compute. I will update once that results in something 😊

Thanks a ton once again for keeping this community updated and contributing, really appreciate it 🙏

Btw, did you join our awesome discord community?

[usrGabriel]

That is awesome, really looking forward to see the new in-browser interface! 😄

I will take a look at joining the Discord for sure.

Thank you!