Update documentation to reflect what is being returned by the API #29
Description
Method client.api.annotation returns a byte stream, but depending on the annotation_format parameter, it can contain a Unicode string or a ZIP file (e.g. with InceptionFormat.UIMA_CAS_XMI_XML_1_0).
Perhaps this is not a big deal since this can be guessed based on how data is provided when exporting manually from Inception, but having this explicitly in the documentation could be helpful.