Configurable path param format

[florian-lefebvre]

I'd like to be able to configure path params to use [id] instead of $id. That could be made available as an option in the config, eg:

export default defineConfig({
  plugins: [
    router({
      routeFilePathParamPattern: '[%s]' // defaults to '$%s' 
    }),
  ],
});

[schiller-manuel]

won't be possible as we also need to parse the path in typescript.
but most likely we will offer both variants in the future for e.g. prefixed path params