Update "Connect to Aiven for Apache Kafka® with Go"

[niklas-lumio-aiven]

What should we add to our content collections?

Now our https://docs.aiven.io/docs/products/kafka/howto/connect-with-go.html instructions has 2 different libraries sarama and kafka-go. Do we want to keep both of these?

Instructions are only for creating producer, which differers from our other documentation e.g. Python and NodeJS.

What I hope to have here:

• Preferably only 1 library, which is considered to be best, so the documentation is not bloated
• Instructions for creating producer and consumer similarly to our other instuctions

Is this something you would work on yourself?

[ ] I plan to open a pull request for this