added link to order book swap prototype repo (#209)

docs/developer-tools/ts-sdk/ts-sdk-intro.md

@@ -43,4 +43,4 @@ These prototypes are released under an open-source license. You can read, deploy
 
 - **[Payouts DApp](payouts-dapp-prototype.md)**: This prototype is an example of a DApp designed to help users discover, track, and withdraw tokens from Marlowe smart contracts that use role tokens. It enables holders of role tokens in Marlowe smart contracts to withdraw the received funds, simplifying the process of tracking and withdrawing their payouts.
 - **[Token Plans DApp GitHub repository](https://github.com/input-output-hk/marlowe-token-plans)**: This prototype is a demonstration of how to build DApps powered by Marlowe with well-known mainstream web technologies such as `TypeScript` and `React Framework`. It is a use case of a vesting contract developed and available in the Marlowe TS-SDK. It allows you to create ada Token Plans over Cardano. Ada Token Plans can be created by a 'token provider.' The token provider will deposit a given amount of ada with a time-based scheme defining how to release these funds to a 'claimer' participant.
-- **Order book swap prototype** (coming soon): This prototype will demonstrate the new Marlowe open roles feature by using a new [**atomic swap contract**](https://github.com/input-output-hk/marlowe-ts-sdk/issues/86). 
+- **[Order book swap prototype](https://github.com/input-output-hk/marlowe-order-book-swap)**: This prototype demonstrates the new Marlowe open roles feature by using a new [**atomic swap contract**](https://github.com/input-output-hk/marlowe-ts-sdk/issues/86).