Using Bio-Formats: Add gradle and maven instructions

I've initially added working examples which use the 5.0.2 artifacts.  It would be nice to have this use `>= |VERSION|` and to preprocess the examples files under `docs/sphinx/developers/artifactory/` to keep the version numbers matching the release.  At the same time, we do need to consider the fact that the links won't be valid up until the artifacts are available.  I've left this hardcoded for now, but it can be adjusted.