Move docker recipe to documentation along with instructions.

[YooSunYoung]

Fixes #99

I removed docker yaml file for kafka and moved the information into the proper documentation under getting-started section.

It also has explanation why it is not included in the hard-dependencies.

[YooSunYoung]

Here is the locally built documentation!
html.zip

[jokasimr]

Looks good to me.

Makes sense to exclude Kafka from the dependencies and put the setup instructions in the documentation instead if Kafka is not the only supported message delivery framework.

Are the Kafka tests run in the CI pipeline? I'm thinking that it is probably good to run them somewhere on a regular basis.

How was the 6GB limit selected?
Do we exceed that limit if we run the benchmark for a longer time period?

[YooSunYoung]

Are the Kafka tests run in the CI pipeline? I'm thinking that it is probably good to run them somewhere on a regular basis.

Not yet, but yes we do need an automated tests. There's an issue regarding this. #97

How was the 6GB limit selected?
Do we exceed that limit if we run the benchmark for a longer time period?

This number was given by ECDC so I think they have tested it within their testing environment.