[docs] Person of interest update: sparse, torchrec and smaller tweaks (#84772)
Fixes #83363
This is not a full update yet, but fixes some obvious things: missing modules (torchrec, sparse) and brings a few people from merge_rules.json who are working on the respective modules. There are still discrepancies - e.g. Intel CPU work is split in many categories in merge_rules, but it's better to improve things incrementally.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84772
Approved by: https://github.com/b0noI, https://github.com/malfet
