[Docs] Include a link to the GitHub repo and Maven Repository

[nlochschmidt]

Currently there seems to be no apparent way to get from https://coworker.kungfury.io/#/ to this repository as there is no link anywhere on the page as far as I can see.

In addition it would be nice to have a maven badge in the docs (and in the project readme as well). This one for example

[Mythra]

Hey @nlochschmidt thanks! TBH Need to merge in quite a few things, but just haven't had time. I'll keep this open but it may be a bit.