fix: re-add yarn prerequisite

arbitrum-docs/build-decentralized-apps/01-quickstart-solidity-remix.mdx

@@ -54,7 +54,7 @@ Let's implement the "Web3" version of the above vending machine using Arbitrum.
   Wallet](https://www.okx.com/web3) and click Connect Wallet to install.
 </CustomDetails>
 
-<CustomDetails summary="Web3 wallet">
+<CustomDetails summary="Yarn">
   The <a data-quicklook-from="ethereum-wallet">wallet</a> we'll use to interact with our vending
   machine. See [metamask.io](https://metamask.io/) and click View MetaMask Web or [OKX
   Wallet](https://www.okx.com/web3) and click Connect Wallet to install.
@@ -65,8 +65,6 @@ Let's implement the "Web3" version of the above vending machine using Arbitrum.
   [getfoundry.sh](https://getfoundry.sh) to install.
 </CustomDetails>
 
-We'll address remaining dependencies as we go.
-
 ### Ethereum and Arbitrum in a nutshell
 
 - **Ethereum**