add metadata for iCell8 test data

## Test data for iCELL8 technique (iCELL8 settings)

### Chips supplied by Takara Bio (11bp barcode, 14bp UMI) 

Citation: Goldstein et al (2017) Massively parallel nanowell-based

single-cell gene expression profiling. BMC Genomics 18, 519

doi: 10.1186/s12864-017-3893-1

## Data source

European Genome-phenome Archive (EGA)

Study Accession: EGAS00001002320

https://ega-archive.org/studies/EGAS00001002320

Data Accession: EGAD00001003443

https://ega-archive.org/datasets/EGAD00001003443

## Data preparations

Filtered for regions mapping to HUMAN_21:9825832-48085036 GRCh38 (hg38)

Matched by fastq_pair (https://github.com/linsalrob/fastq-pair)