Convert SingleCellNearestNeighbour to manifoldsR NearestNeighbours
sc_knn_to_nearest_neighbours.RdConverts the bixverse single cell kNN class into the manifoldsR
NearestNeighbours class for use in UMAP, tSNE, etc. Note that the
bixverse class stores 0-indexed indices whereas manifoldsR expects
1-indexed, so the conversion handles that.