Fix example project file in importer documentation
Fix example project file in importer documentation

It was lacking some required keywords and the opacity was in the wrong range.

htem/CATMAID,fzadow/CATMAID,fzadow/CATMAID,fzadow/CATMAID,htem/CATMAID,htem/CATMAID,fzadow/CATMAID,htem/CATMAID