Update script so you can pass data dir on command-line
Update script so you can pass data dir on command-line

bash ~/svn/cctbx/sources/dials/doc/user/tutorial.sh ~/data/i04-BAG-training/

Also include some error trapping 

bash ~/svn/cctbx/sources/dials/doc/user/tutorial.sh ~/data/nonsense/
Data not found in directory: /Users/graeme/data/nonsense/ -
please download from doi:10.5281/zenodo.10271 and pass on command-line
or create softlink from data directory to ./data

dials/dials,dials/dials,dials/dials,dials/dials,dials/dials