Improve quickstart so that it takes into account all latest developments in the SDK

[atsakiridis]

The way things are now the developer doesn't need to download a custom bundle. Once we cut a release they should be able to just download default release .zip (provided by GitHub automatically), since all dependencies are uploaded to maven repos

Also consider the whole Quick Start approach and whether we should mention all possible cases (i.e. docker and cloud)

Finally, need to also specify the needed App manifest permissions, if there are any