docs(www): fix diff for peerDependencies (shadcn-ui#5640)

Co-authored-by: shadcn <[email protected]>

apps/www/content/docs/react-19.mdx

@@ -22,10 +22,12 @@ React 19 is now [rc](https://www.npmjs.com/package/react?activeTab=versions) and
 
 To support React 19, package maintainers will need to test and update their packages to include React 19 as a peer dependency. This is [already](https://github.com/radix-ui/primitives/pull/2952) [in](https://github.com/pacocoursey/cmdk/pull/318) [progress](https://github.com/emilkowalski/vaul/pull/498).
 
-```diff /^19.0.0/
+```diff /^19.0/
 "peerDependencies": {
 -  "react": "^16.8 || ^17.0 || ^18.0",
-+  "react": "^16.8 || ^17.0 || ^18.0 || ^19.0"
++  "react": "^16.8 || ^17.0 || ^18.0 || ^19.0",
+-  "react-dom": "^16.8 || ^17.0 || ^18.0"
++  "react-dom": "^16.8 || ^17.0 || ^18.0 || ^19.0"
 },
 ```