Adding data / metadata pointers

[emdann]

From user feedback:

• [x] Add sample metadata .csv with matching of VDJ libraries to RNA libraries

• [x] Move BCR libraries in contig folders

• [x] Fix assignment of image IDs in spatial objects .obs

• [x] Add TCR/BCR contig data to the data portal https://cellgeni.cog.sanger.ac.uk/developmentcellatlas/fetal-immune/panfetal_BCR.tar.gz https://cellgeni.cog.sanger.ac.uk/developmentcellatlas/fetal-immune/panfetal_abTCR.tar.gz

• [x] Make metadata .yaml for sfaira and store in metadata/

• [x] 5' v1 in main scRNA-seq libs, 5' v2 for ATO

• [x] Add ALL data location info to README

[emdann]

To mp:

• new tarballs
• sample metadata
• fixed visium objects

To dh:

• Change DOI to science paper
• fix 5' v1
• link to tarballs
• Link to sample metadata