Example for SASL_SSL with Kerberos

[Knappek]

First of all, thank you for this repo, it's awesome, I love it!

This repo has a running example for kerberized Kafka using SASL_PLAINTEXT, it would be great to have an example with SASL_SSL as well.

Does that make sense? If so, I can also contribute it.

[Dabz]

I am not sure that it would make sense, although that Kerberos + TLS are quite frequent, both configurations are quite complicated to automate (KDC + Certificates generation) and I am not sure I would like to start providing examples for each possible combination ;)
Of course, a contribution is always welcome, I would gladly review and merge a PR if someone open one ;)