docs: fix spacing in installation instructions (#79257)

This PR fixes a minor spacing issue in the "Run the development server"
section of the installation guide.

No functionality is affected.

---------

Co-authored-by: JJ Kasper <jj@jjsweb.site>

Author: Macw07

docs/01-app/01-getting-started/01-installation.mdx

@@ -226,7 +226,7 @@ export default function Page() {
 
 1. Run `npm run dev` to start the development server.
 2. Visit `http://localhost:3000` to view your application.
-3. Edit the<AppOnly>`app/page.tsx`</AppOnly> <PagesOnly>`pages/index.tsx`</PagesOnly> file and save it to see the updated result in your browser.
+3. Edit the <AppOnly>`app/page.tsx`</AppOnly><PagesOnly>`pages/index.tsx`</PagesOnly> file and save it to see the updated result in your browser.
 
 ## Set up TypeScript