doc: Update tailwind generation doc

Author: mcmah309

README.md

@@ -10,7 +10,7 @@ rehydrated with interactivity provided by `dioxus_web`.
 The docsite uses the newest Tailwind (v4) so you need to install it first and then run it using:
 
 ```sh
-npx @tailwindcss/cli -i ./tailwind.css -o ./assets/tailwind.css --watch
+npx @tailwindcss/cli -i ./tailwind.css -o ./packages/docsite/assets/tailwind.css --watch
 ```
 
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