fix(docs): add fee sponsoring overview

apps/docs/pages/sdk/guides/sponsoring.mdx

@@ -3,8 +3,19 @@ import { GuideDemoContainer } from '../../../components/GuideDemoContainer'
 
 # Fee Sponsoring
 
-This guide will demonstrate how you can leverage Fee Sponsoring in your Application to cover
-fees for your users.
+A Porto Merchant (Sponsor) Account lets your app pay gas on behalf of users.
+It is an admin-controlled account that, via your Merchant RPC server,
+designates itself as the fee payer and signs fee payments for user calls.
+This flow allows you to sponsor or subsidize any transaction fee.
+
+## Usage
+
+- Expose a Merchant RPC endpoint that inspects requests and attaches fee sponsorship
+- (Optional) If your server is remote, pass `merchantRpcUrl` to `Porto.create()`
+- You can add conditional rules with the `sponsor` option to control when fees are covered
+
+The guide below will show you how to set up a Merchant RPC server and how to use it with Porto
+using a Cloudflare Worker, but you can also use any other server framework (Next.js, Deno, Express, etc).
 
 ## Template
 
@@ -49,9 +60,7 @@ MERCHANT_PRIVATE_KEY=0x...
 ### Set up Merchant RPC Server
 
 Next, we will set up our Merchant RPC Server at the `/rpc` endpoint of our app.
-For this example, we will use a Cloudflare Worker, however, you could also use a
-server framework of your choice (Next.js, Deno, Express, etc).
-See the [`MerchantRpc` API reference](/sdk/api/merchantRpc/requestHandler).
+See the [`MerchantRpc`](/sdk/api/merchantRpc/requestHandler) API reference for more details.
 
 ```ts
 import { env } from 'cloudflare:workers'
@@ -86,7 +95,7 @@ const porto = await Porto.create({
 
 ### Done
 
-That's it! Once you have a server set up at the `/rpc` path of your app (or another remote URL), Porto will automatically
-detect it and route through this endpoint for future calls to perform (and sponsor) a transaction.
+That's it! Once you have a server set up at the `/rpc` path of your app (or another remote URL),
+Porto will route through this endpoint for future calls to perform (and sponsor) a transaction.
 
 ::::