docs(vite-plugin-svelte): update readme

Author: dominikg

packages/vite-plugin-svelte/README.md

@@ -12,8 +12,7 @@ module.exports = defineConfig(({ command, mode }) => {
   return {
     plugins: [
       svelte({
-        hot: !isProduction,
-        emitCss: true
+        /* inline options here */
       })
     ],
     build: {
@@ -25,9 +24,19 @@ module.exports = defineConfig(({ command, mode }) => {
 
 ## Options
 
-```ts
-// TODO
-```
+vite-plugin-svelte reads the vite configuration and uses an appropriate default configuration
+
+It also loads `svelte.config.js` (or `svelte.config.cjs`) from the configured `vite.root` directory automatically.
+
+Options are applied in the following order:
+
+1. vite-plugin-svelte defaults
+2. svelte.config.js in vite.root
+3. inline options passed in vite.config.js
+
+It supports all options from rollup-plugin-svelte and some additional options to tailor the plugin to your needs.
+
+For more Information check [options.ts](packages/vite-plugin-svelte/src/utils/options.ts)
 
 ## License