nanshe/nanshe/registration.py: Added documentation to dtfreg_fast_shifts to explain template_fft.
nanshe/nanshe/registration.py: Added documentation to dtfreg_fast_shifts to explain template_fft.

jakirkham/nanshe,DudLab/nanshe,nanshe-org/nanshe,DudLab/nanshe,jakirkham/nanshe,nanshe-org/nanshe