[Docs RFC] Create a doc showing how to integrate Apache Kafka with Timescale Cloud

[atovpeko]

Validate that the procedure in the document works, update the doc supplied in the branch in line with the template (if needed), and follow the google style guide.

Template: https://github.com/timescale/docs/blob/latest/.github/styles/templates/integration.md
Doc draft: in the linked PR

This is a reduced version of the this blog post: https://www.timescale.com/blog/building-a-kafka-data-pipeline-for-time-series-with-kafka-connect-and-timescale (if needed for reference or to clarify details).