Create the SDK integration guide for building an Order Book

[gustavobftorres]

Parent

LIME-Protocol/lime-onchain#3

What to build

Write the developer guide for building an Order Book on LIME using @lime/solana, Signed Orders, and non-trusted matching.

Acceptance criteria

• Guide shows the end-to-end flow from deposit to signOrder to matching to settleSignedOrders
• Guide explains how to read fill state and remaining Quantity
• Guide explains backend responsibilities and limits
• Guide includes setup steps for localnet or devnet
• Guide links to the reference Order Book implementation

Blocked by

• https://github.com/LIME-Protocol/lime-sdk/issues/4
• Refactor the reference Order Book to consume Signed Orders lime-backend#2