update the running instructions

README.md

@@ -22,7 +22,7 @@ With [dioxus] installed, you can use it to build and serve the documentation on
 dx serve --example spa --features web
 ```
 
-this will start a local server that will be available on [localhost](http://localhost:3000) and will automatically build and re-build the documentation when it changes.
+this will start a local server that will be available on [localhost](http://localhost:8080) and will automatically build and re-build the documentation when it changes.
 
 ## Contributing
 Want to help out? Check out our [The "Contributing" document][contributing]