Improve Svelte README (#5923)

* First stylistic pass

* Rework for x/o instead of and

* fix typo

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

* Add changeset

Co-authored-by: Sarah Rainsberger <sarah@rainsberger.ca>

.changeset/lucky-ants-push.md

@@ -0,0 +1,5 @@
+---
+"@astrojs/svelte": patch
+---
+
+Improve README

packages/integrations/svelte/README.md

@@ -74,11 +74,11 @@ This package is maintained by Astro's Core team. You're welcome to submit an iss
 
 ## Options
 
-This integration is powered by `@sveltejs/vite-plugin-svelte`. To customize the Svelte compiler, options can be provided to the integration. See the `@sveltejs/vite-plugin-svelte` [docs](https://github.com/sveltejs/vite-plugin-svelte/blob/HEAD/docs/config.md) for more details.
+This integration is powered by `@sveltejs/vite-plugin-svelte`. To customize the Svelte compiler, options can be provided to the integration. See the [`@sveltejs/vite-plugin-svelte` docs](https://github.com/sveltejs/vite-plugin-svelte/blob/HEAD/docs/config.md) for more details.
 
 ### Default options
 
-A few of the default options passed to the Svelte compiler are required to build properly for Astro and cannot be overridden.
+This integration passes the following default options to the Svelte compiler:
 
 ```js
 const defaultOptions = {
@@ -88,40 +88,39 @@ const defaultOptions = {
 };
 ```
 
-The `emitCss`, `compilerOptions.dev`, and `compilerOptions.hydratable` cannot be overridden.
+These `emitCss`, `compilerOptions.dev`, and `compilerOptions.hydratable` values are required to build properly for Astro and cannot be overridden.
 
-Providing your own `preprocess` options **will** override the defaults - make sure to enable the preprocessor flags needed for your project. For example,
+Providing your own `preprocess` options **will** override the [`vitePreprocess()`](https://github.com/sveltejs/vite-plugin-svelte/blob/HEAD/docs/preprocess.md) default. Make sure to enable the preprocessor flags needed for your project.
+
+You can set options either by passing them to the `svelte` integration in `astro.config.mjs` or in `svelte.config.js`. Either of these would override the default `preprocess` setting:
 
 ```js
-// astro.config.js
+// astro.config.mjs
 import svelte from '@astrojs/svelte';
 
 export default {
   integrations: [svelte({ preprocess: [] })],
 };
 ```
 
-and
-
 ```js
 // svelte.config.js
 export default {
   preprocess: [],
 };
 ```
 
-Will override the default `preprocess` option. You can read the [`vitePreprocess` docs](https://github.com/sveltejs/vite-plugin-svelte/blob/HEAD/docs/preprocess.md) for more information of how it works.
-
 ## Intellisense for TypeScript
 
-If you're using a preprocessor like TypeScript or SCSS in your Svelte files, you can create a `svelte.config.js` file with:
+If you're using a preprocessor like TypeScript or SCSS in your Svelte files, you can create a `svelte.config.js` file so that the Svelte IDE extension can correctly parse the Svelte files.
 
 ```js
+// svelte.config.js
 import { vitePreprocess } from '@astrojs/svelte';
 
 export default {
 	preprocess: vitePreprocess(),
 };
 ```
 
-So the Svelte IDE extension can correctly parse the Svelte files. This config file is added by default when you run `astro add svelte`.
+This config file will be automatically added for you when you run `astro add svelte`.