add more conceptual info to personalization

Author: ethanpalm

authentication-personalization/personalization-setup.mdx

@@ -4,7 +4,65 @@ description: "Let users log in for customized documentation experiences"
 icon: "user-cog"
 ---
 
-Customize your documentation based on user information, including prefilling API playground inputs and adding dynamic content.
+Personalization customizes your documentation for each user when they are logged in. For example, you can prefill their API keys, show content specific to their plan or role, or hide sections they don't need access to.
+
+## Personalized content
+
+Personalization allows you to customize content with these features.
+
+### API key prefilling
+
+Automatically populate API playground fields with user-specific values by returning matching field names in your user data. The field names in your user data must exactly match the names in the API playground for automatic prefilling to work.
+
+### Dynamic MDX content
+
+Display dynamic content based on user information like name, plan, or organization.
+
+The `user` variable contains information sent to your docs from logged in users. See the [User data format](#user-data-format) section below for more information.
+
+**Example**: Hello, {user.name ?? 'reader'}!
+
+```jsx
+Hello, {user.name ?? 'reader'}!
+```
+
+This feature is more powerful when you pair it with custom data about your users. For example, you can give different instructions based on a user's plan.
+
+**Example**: Authentication is an enterprise feature. {
+user.org === undefined
+? <>To access this feature, first create an account at the <a href="https://dashboard.mintlify.com/login">Mintlify dashboard</a>.</>
+: user.org.plan !== 'enterprise'
+? <>You are currently on the ${user.org.plan ?? 'free'} plan. See <a href="https://mintlify.com/pricing">our pricing page</a> for information about upgrading.</>
+: <>To request this feature for your enterprise org, contact your admin.</>
+}
+
+```jsx
+Authentication is an enterprise feature. {
+  user.org === undefined
+    ? <>To access this feature, first create an account at the <a href="https://dashboard.mintlify.com/login">Mintlify dashboard</a>.</>
+    : user.org.plan !== 'enterprise'
+      ? <>You are currently on the ${user.org.plan ?? 'free'} plan. See <a href="https://mintlify.com/pricing">our pricing page</a> for information about upgrading.</>
+      : <>To request this feature for your enterprise org, contact your admin.</>
+}
+```
+
+<Note>
+  The information in `user` is only available for logged in users. For logged out users, the value of `user` will be `{}`. To prevent the page from crashing for logged out users, always use optional chaining on your `user` fields. For example, `{user.org?.plan}`.
+</Note>
+
+### Page visibility
+
+Restrict which pages are visible to your users by adding `groups` fields to your pages' frontmatter. By default, every page is visible to every user.
+
+Users will only see pages for `groups` that they are in.
+
+```mdx
+---
+title: "Managing your users"
+description: "Adding and removing users from your organization"
+groups: ["admin"]
+---
+```
 
 ## User data format
 
@@ -306,4 +364,3 @@ No CORS configuration is needed since the dashboard and docs share the same doma
 </Note>
   </Tab>
 </Tabs>
-