docs: clean up referral docs

Remove e.g. examples from referral params in what-we-collect, and
rewrite the Web SDK referrals example to use the FormoAnalyticsProvider
options format matching the Wagmi integration example.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: yosriady

data/what-we-collect.mdx

@@ -180,8 +180,8 @@ They are added to a URL to track where a visitor came from.
 
 We track these UTM codes and assign it to each user:
 
-- `referral` (e.g.: google.com)
-- `ref` (e.g.: search)
+- `referral`
+- `ref`
 - `refcode`
 
 ### Wallet Provider

sdks/web.mdx

@@ -679,13 +679,16 @@ const analytics = await FormoAnalytics.init('YOUR_API_KEY', {
 
 Formo autodetects `ref`, `referral`, and `refcode` query parameters in the URL. You can customize how referrals are detected by the SDK:
 
-```javascript
-const analytics = await FormoAnalytics.init('YOUR_API_KEY', {
-  referral: {
-    queryParams: ['via', 'ref'],
-    pathPattern: '/referral/([^/]+)'
-  }
-});
+```tsx
+<FormoAnalyticsProvider
+  writeKey="<YOUR_WRITE_KEY>"
+  options={{
+    referral: {
+      queryParams: ['via', 'ref'],      // Query params to detect (default: ['ref', 'referral', 'refcode'])
+      pathPattern: '/referral/([^/]+)', // Regex to extract referral code from the URL path
+    },
+  }}
+>
 ```
 
 In the above configuration, Formo will detect referrals from: