feat: Mention that the cookie-sync extension works for previews (#12858)

* feat: Mention that the cookie-sync extension works for previews

* Update develop-docs/development-infrastructure/frontend-development-server.mdx

* Update develop-docs/development-infrastructure/frontend-development-server.mdx

Co-authored-by: Michelle Zhang <56095982+michellewzhang@users.noreply.github.com>

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Co-authored-by: Michelle Zhang <56095982+michellewzhang@users.noreply.github.com>

develop-docs/development-infrastructure/frontend-development-server.mdx

@@ -15,7 +15,7 @@ The development server can be viewed at [https://dev.getsentry.net:7999](https:/
 
 In any case, you can now login to your development server with your Sentry.io credentials. The SSO-login flow will *NOT* work. Only email/password is supported on the login form in development.
 
-While the SSO-login flow will not work, cookies from an existing logged-in sessions will work correctly. You may use our [Cookie Sync](https://github.com/getsentry/cookie-sync) browser extension to sync session cookies from `*.sentry.io` domain and into `*.dev.getsentry.net` domain in your browser.
+While the SSO-login flow will not work, cookies from an existing logged-in sessions will work correctly. You may use our [Cookie Sync](https://github.com/getsentry/cookie-sync) browser extension to sync session cookies from `*.sentry.io` into `*.dev.getsentry.net`, and `*.sentry.dev` -- the latter being the Github Preview environment hosted on Vercel.
 
 - [Get Cookie Sync for Chrome](https://chrome.google.com/webstore/detail/sentry-cookie-sync/kchlmkcdfohlmobgojmipoppgpedhijh)
 - [Get Cookie Sync for Firefox](https://addons.mozilla.org/en-US/firefox/addon/sentry-cookie-sync/)