Could you elaborate on the process of adding Zeta to MetaMask? I'm curious to understand the steps involved as I'm a crypto enthusiast who's interested in diversifying my portfolio. Would it require adding a custom token or is there a specific way to integrate Zeta's smart contract? I'm also wondering if there are any additional considerations or precautions I should take to ensure a smooth and secure process. Your expertise in this area would be greatly appreciated in guiding me through this procedure.