Bug: Add Viem + Wagmi guides for Flashblocks

### Describe the bug

x

### Steps

1. Visit https://docs.base.org/chain/flashblocks/apps
2. Viem + Wagmi is "coming soon", but it's already here! 
  a. see: https://x.com/_jxom/status/1927366613994455362

### Expected behavior

A guide for Viem + Wagmi :)

### Additional info

_No response_

### Environment

_No response_