Minor Points JSON sidecar files in sourcedata

The JSON sidecar files in sourcedata can be modified in the following points (see Markus mail)

"InstitutionName": "Forschungszentrum Jülich GmbH",

"SampleFixation": "4% formaldehyde fixation",

"SampleStaining": [ "Merker silver staining" (Silver staining of cell bodies by means of physical development, B. Merker, PMID: 6198563, DOI: 10.1016/0165-0270(83)90086-9) ],

"SampleExtractionProtocol": "whole brain post mortem extraction",

"SampleExtractionInstitution": "Forschungszentrum Jülich GmbH"