Update bundle return table (re-measured 5ep seed=0 CPU; reflects new ant-v5 & humanoid-v5 bundles)

Update humanoid-v5 bundle (50ep eval: mean 3058 -> 4571, median 2330 -> 4882, surv 3/50 -> 15/50; context_length 24 -> 32)

Update ant-v5 bundle (50ep eval: mean 1914 -> 2265, median 1562 -> 1969; context_length 24 -> 16)

Sync README with repo: drop device=cpu, drop ?nw, add return numbers

Add model card

Add humanoid-v5 bundle

Add walker2d-v5 bundle

Add halfcheetah-v5 bundle

Upload ant-v5 test bundle

initial commit