Mostly missing in docs, have to rewrite from whitepapers

Serialize 1 cell: https://docs.ton.org/v3/documentation/data-formats/cells/serialization
Combine into BoC: https://docs.ton.org/v3/documentation/data-formats/cells/overview#bag-of-cells

What are multiroot BoC for?

Should give examples of @ton/core:

• serializing and deserializing cells
• both hex and base64