Update doc links for geolocation example (#1103)

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### Type of Change

- [ ] New Example
- [ ] Example updates (Bug fixes, new features, etc.)
- [ ] Other (changes to the codebase, but not to examples)

### New Example Checklist

- [ ] 🛫 `npm run new-example` was used to create the example
- [ ] 📚 The template wasn't used but I carefuly read the [Adding a new
example](https://github.com/vercel/examples#adding-a-new-example) steps
and implemented them in the example
- [ ] 📱 Is it responsive? Are mobile and tablets considered?

Author: ismaelrumzan

edge-middleware/geolocation/pages/index.tsx

@@ -32,7 +32,7 @@ export default function Index({
         </p>
         <a
           className="flex items-center mt-4 text-md sm:text-lg text-blue-500 hover:underline"
-          href="https://vercel.com/docs/edge-network/headers#request-headers?utm_source=geo-ip-demo&utm_campaign=geo-ip-demo"
+          href="https://vercel.com/docs/edge-network/headers/request-headers#x-vercel-ip-continent?utm_source=geo-ip-demo&utm_campaign=geo-ip-demo"
           target="_blank"
           rel="noreferrer"
         >

edge-middleware/i18n/pages/[locale]/[country].tsx

@@ -60,7 +60,7 @@ export default function CountryPage({ country, locale, dictionary }: Props) {
           </p>
           <a
             className="flex items-center mt-4 text-md sm:text-lg text-blue-500 hover:underline"
-            href="https://vercel.com/docs/edge-network/headers#request-headers?utm_source=geo-ip-demo&utm_campaign=geo-ip-demo"
+            href="https://vercel.com/docs/edge-network/headers/request-headers#x-vercel-ip-continent?utm_source=geo-ip-demo&utm_campaign=geo-ip-demo"
             target="_blank"
             rel="noreferrer"
           >

edge-middleware/power-parity-pricing/pages/[country].tsx

@@ -68,7 +68,7 @@ export default function CountryPage({ country, parity }) {
         </p>
         <a
           className="flex items-center mt-4 text-md sm:text-lg text-blue-500 hover:underline"
-          href="https://vercel.com/docs/edge-network/headers#request-headers?utm_source=geo-ip-demo&utm_campaign=geo-ip-demo"
+          href="https://vercel.com/docs/edge-network/headers/request-headers#x-vercel-ip-continent?utm_source=geo-ip-demo&utm_campaign=geo-ip-demo"
           target="_blank"
           rel="noreferrer"
         >