docs: expo installation command

Author: ankit-tailor

docs/docs/getting-started/web.mdx

@@ -21,7 +21,7 @@ You can use React Native Skia without React Native Web.
 Using React Native Skia on Expo web is reasonably straightforward.
 We provide a script that will work well with the setup:
 ```bash
-$ expo install @shopify/react-native-skia
+$ npx expo install @shopify/react-native-skia
 $ yarn setup-skia-web
 ```