docs(quickstart/01-getting-started.jmd): Include callbacks examples
docs(quickstart/01-getting-started.jmd): Include callbacks examples

Hoping integrators are less confused with examples on using callbacks
in (non-)jQuery mode(s) included...

fixes #969

[ci skip]

FineUploader/fine-uploader,FineUploader/fine-uploader,FineUploader/fine-uploader