docs: Change Storybook install documentation (#5779)

docusaurus/docs/developing-components-in-isolation.md

@@ -31,7 +31,7 @@ npm install -g @storybook/cli
 Then, run the following command inside your app’s directory:
 
 ```sh
-getstorybook
+sb init
 ```
 
 After that, follow the instructions on the screen.