DOC: ExternalData: Update documentation to match CMake copy
DOC: ExternalData: Update documentation to match CMake copy

Change-Id: I0ffa1b2b1f86d305e4eaf4d4efd272e3f85c3fa9

biotrump/ITK,spinicist/ITK,InsightSoftwareConsortium/ITK,spinicist/ITK,blowekamp/ITK,richardbeare/ITK,InsightSoftwareConsortium/ITK,LucasGandel/ITK,blowekamp/ITK,InsightSoftwareConsortium/ITK,BlueBrain/ITK,thewtex/ITK,PlutoniumHeart/ITK,stnava/ITK,stnava/ITK,BlueBrain/ITK,malaterre/ITK,richardbeare/ITK,LucHermitte/ITK,Kitware/ITK,zachary-williamson/ITK,biotrump/ITK,Kitware/ITK,malaterre/ITK,PlutoniumHeart/ITK,malaterre/ITK,blowekamp/ITK,thewtex/ITK,jmerkow/ITK,hjmjohnson/ITK,atsnyder/ITK,spinicist/ITK,jcfr/ITK,BRAINSia/ITK,malaterre/ITK,richardbeare/ITK,msmolens/ITK,atsnyder/ITK,jcfr/ITK,msmolens/ITK,stnava/ITK,spinicist/ITK,biotrump/ITK,hjmjohnson/ITK,spinicist/ITK,LucasGandel/ITK,msmolens/ITK,biotrump/ITK,BlueBrain/ITK,jcfr/ITK,vfonov/ITK,LucHermitte/ITK,jcfr/ITK,jmerkow/ITK,msmolens/ITK,LucHermitte/ITK,malaterre/ITK,stnava/ITK,ajjl/ITK,atsnyder/ITK,jcfr/ITK,biotrump/ITK,BRAINSia/ITK,atsnyder/ITK,vfonov/ITK,jmerkow/ITK,InsightSoftwareConsortium/ITK,biotrump/ITK,biotrump/ITK,fbudin69500/ITK,fedral/ITK,BlueBrain/ITK,atsnyder/ITK,BRAINSia/ITK,fedral/ITK,biotrump/ITK,msmolens/ITK,blowekamp/ITK,fbudin69500/ITK,blowekamp/ITK,Kitware/ITK,msmolens/ITK,stnava/ITK,spinicist/ITK,jcfr/ITK,fedral/ITK,fedral/ITK,BlueBrain/ITK,msmolens/ITK,zachary-williamson/ITK,PlutoniumHeart/ITK,InsightSoftwareConsortium/ITK,msmolens/ITK,jmerkow/ITK,BRAINSia/ITK,spinicist/ITK,vfonov/ITK,BlueBrain/ITK,atsnyder/ITK,fbudin69500/ITK,richardbeare/ITK,PlutoniumHeart/ITK,zachary-williamson/ITK,ajjl/ITK,fbudin69500/ITK,malaterre/ITK,fbudin69500/ITK,LucHermitte/ITK,LucasGandel/ITK,jmerkow/ITK,vfonov/ITK,fbudin69500/ITK,LucHermitte/ITK,hjmjohnson/ITK,BRAINSia/ITK,stnava/ITK,jcfr/ITK,vfonov/ITK,LucasGandel/ITK,PlutoniumHeart/ITK,richardbeare/ITK,malaterre/ITK,jmerkow/ITK,ajjl/ITK,thewtex/ITK,vfonov/ITK,Kitware/ITK,LucHermitte/ITK,zachary-williamson/ITK,malaterre/ITK,LucasGandel/ITK,hjmjohnson/ITK,ajjl/ITK,atsnyder/ITK,LucHermitte/ITK,vfonov/ITK,jmerkow/ITK,thewtex/ITK,zachary-williamson/ITK,LucasGandel/ITK,zachary-williamson/ITK,richardbeare/ITK,jmerkow/ITK,vfonov/ITK,thewtex/ITK,Kitware/ITK,atsnyder/ITK,fedral/ITK,stnava/ITK,BRAINSia/ITK,ajjl/ITK,blowekamp/ITK,hjmjohnson/ITK,zachary-williamson/ITK,stnava/ITK,fbudin69500/ITK,atsnyder/ITK,fedral/ITK,thewtex/ITK,hjmjohnson/ITK,PlutoniumHeart/ITK,spinicist/ITK,zachary-williamson/ITK,LucHermitte/ITK,BlueBrain/ITK,ajjl/ITK,zachary-williamson/ITK,blowekamp/ITK,PlutoniumHeart/ITK,PlutoniumHeart/ITK,spinicist/ITK,LucasGandel/ITK,hjmjohnson/ITK,blowekamp/ITK,InsightSoftwareConsortium/ITK,BlueBrain/ITK,thewtex/ITK,Kitware/ITK,LucasGandel/ITK,ajjl/ITK,BRAINSia/ITK,fedral/ITK,fbudin69500/ITK,fedral/ITK,malaterre/ITK,ajjl/ITK,InsightSoftwareConsortium/ITK,richardbeare/ITK,vfonov/ITK,jcfr/ITK,stnava/ITK,Kitware/ITK