fix start command in the readme

[aminya]

No description provided.

[amoutonbrady]

Ah, thank you! I generally prefer the dev script but in order to stay consistent with create-solid-app, I left the start script on the default vite js/ts template.

[aminya]

Start actually starts a server, so it makes sense.

I think "dev" should be left for "watch" mode. It is not added yet:
vitejs/vite#1434