script to generate T1w_dtissue json file

[Paolopost]

simply one copy of labels coding

[francopestilli]

@Paolopost I do not understand what thisis about. It woudl be great if you could comemnt more exstensively for me.

@andnp Andrew seems to know what thisis about and will check with @shilcoop whether she has completed a script that we can use.

Deadline Fri Jan 27. Two weeks from now.