Documentation Request: Update the Paymaster Bundler experience Guide

[cpcramer]

Is your documentation request related to a problem? Please describe.

The guide feels disconnected on how the code is now. We need to re-write it in a way the guides helps understand the code inside BOAT.

Update the code to match what's in BOAT as well as the format of the guide.

What's the correct response for this?

Select Onchain App experiences (press space to remove an experience)
│  Paymaster Bundler
│
▲  Base RPC URL
│  https://sepolia.base.org_
└  RPC must be at least 79 characters

[sergical]

I got my RPC URL from https://portal.cdp.coinbase.com/products/node however, I am stuck on the experience as well since the internal API endpoint for api/rpc is telling me

POST /api/rpc 500 in 7ms
Error: TypeError: Request with GET/HEAD method cannot have body.