SHREC'21 training data in pickle form at 10A

Shrec'21 dataset stored in a format for training an alignment model. Archive contains both a zip with ground truth tilt-series and torch-tiltxcorr (see github) alignments. For each tilt-series a .pickle is stored that contains the tilt-series images downsampled to 10A together with a set of alignments (translations, tilt angles, tilt axis angles). They can be loaded to a Tomogram object (as available in torch-tomogram, see github).