fix: some beta docs based on feedback (#2507)

src/pages/migrating/guide/develop.mdx

@@ -73,7 +73,7 @@ npm -i @carbon/react
 ```
 
 ```
-yarn install @carbon/react
+yarn add @carbon/react
 ```
 
 2. Remove the old packages
@@ -86,6 +86,15 @@ npm uninstall carbon-components carbon-components-react carbon-icons
 yarn remove carbon-components carbon-components-react carbon-icons
 ```
 
+<InlineNotification>
+
+While this release is still in beta, you may have to keep `carbon-components`,
+`carbon-components-react` and `carbon-icons` installed since `@carbon/react` is
+importing them. In the future, these will be included as peer dependencies in
+the package, and you won't have to install them.
+
+</InlineNotification>
+
 3. Update package imports. Migration for this can be as easy as
    find-and-replace. Search for anywhere you're importing components or icons
    and update the import to point to `@carbon/react`. Read the next section
@@ -100,10 +109,10 @@ function MyComponent() {
 ```
 
 ```js
-import { Add } from '@carbon/react/icons';
+import { Add16 } from '@carbon/react/icons';
 
 function MyComponent() {
-  return <Add />;
+  return <Add16 />;
 }
 ```
 
@@ -449,11 +458,9 @@ theming, or render a theme for an entire page.
 Here is an example of how you can use the `Theme` component:
 
 ```jsx
-import { g90 } from '@carbon/themes';
-
-<Theme theme={g90}>
+<Theme theme="g90">
   <ChildComponent />
-</Theme>;
+</Theme>
 ```
 
 To learn more about how our `Theme` component works with our `useTheme` hook,