PIP-46 Add SUSHI to DEFI+L

Forum discussion: https://forum.piedao.org/t/pip-46-re-balance-defi-l-to-include-sushi-and-yass-sub-pie/403/15

This proposal is for the addition of SUSHI to DEFI+L only, and not the YASS sub PieVault.

Sushiswap has grown in both marketcap and DEX volume share and is a clear contender for inclusion in our large market cap DEFI pie DEFI+L.

Should PieDAO rebalance DEFI+L to include SUSHI as per the allocation outlined in the forum discussion.