add_meta_data_cds: Add colData (aka pData) to a cell_data_set
In scfurl/m3addon: This package adds to the popular "monocle3"

This function will take a cds and add sample levels phenodata to all the cells from that

1	add_meta_data_cds(cds, meta, cds_col = "sample", meta_col = "sample")

`folders`	A vector of cellranger folders (full folder name is ideal). These must contain an "outs" subfolders with two files; 1) raw_feature_bc_matrix.h5, and 2) filtered_feature_bc_matrix.h5. For aggregated samples run with cellrangers 'aggregate' function, this folder should also contain the aggregation.csv file.
`samplenames`	An optional vector that corresponds to the names you would like to give to each element in filelist. This defaults to the the basename of the filelist element i.e.
`unfiltered`	This parameter, if true, returns a list containing 1) the filtered cds, 2) a list of unfiltered cds for each sample in 'folders'.
`empty.droplet.threshold`	minimum number of umis per droplet to include in unfiltered output (default 15)
`expressed_genes`	If true, this option removes genes that do not have expression in at least a minumum number of cells (cell_min parameter)
`cell_min`	Minimum number of cells that a gene needs to be expressed for the gene to be included in the
`aggregated`	will read a cellranger aggregate folder, this is currently only supported for 1 folder. The 'aggregation.csv' file must be included in the 'outs' folder.