Add maven dependencies declaration docs

[dybarsky]

Gradle allows to include all artefacts from group, but maven doesn't. That means, it's needed to specify all jvm targeting artefacts explicitly as dependencies. Adding this part to documentation, so people who don't know much about kotlin multiplatform internals may find it easier to add dependency into project

[dybarsky]

@jillesvangurp thanks

[dybarsky]

@jillesvangurp I have a question. I realized README.md was not updated after merge. Do I need to do something extra to generate new readme file and than commit it as a separate PR? Or is it being updated automatically?

[jillesvangurp]

Ah right, you should have run the tests in docs to regenerate the README before creating the PR. No problem, I just re-ran that and pushed the changes.