docs: add tsconfig.json info to TS docs (#14519)

Also fix adjacent code examples

closes #14187

documentation/docs/07-misc/03-typescript.md

@@ -40,26 +40,26 @@ If you want to use one of these features, you need to setup up a `script` prepro
 
 To use non-type-only TypeScript features within Svelte components, you need to add a preprocessor that will turn TypeScript into JavaScript.
 
-### Using SvelteKit or Vite
-
-The easiest way to get started is scaffolding a new SvelteKit project by typing `npx sv create`, following the prompts and choosing the TypeScript option.
-
 ```ts
 /// file: svelte.config.js
 // @noErrors
-import { vitePreprocess } from '@sveltejs/kit/vite';
+import { vitePreprocess } from '@sveltejs/vite-plugin-svelte';
 
 const config = {
-	preprocess: vitePreprocess()
+	// Note the additional `{ script: true }`
+	preprocess: vitePreprocess({ script: true })
 };
 
 export default config;
 ```
 
-If you don't need or want all the features SvelteKit has to offer, you can scaffold a Svelte-flavoured Vite project instead by typing `npm create vite@latest` and selecting the `svelte-ts` option.
+### Using SvelteKit or Vite
+
+The easiest way to get started is scaffolding a new SvelteKit project by typing `npx sv create`, following the prompts and choosing the TypeScript option.
 
 ```ts
 /// file: svelte.config.js
+// @noErrors
 import { vitePreprocess } from '@sveltejs/vite-plugin-svelte';
 
 const config = {
@@ -69,6 +69,8 @@ const config = {
 export default config;
 ```
 
+If you don't need or want all the features SvelteKit has to offer, you can scaffold a Svelte-flavoured Vite project instead by typing `npm create vite@latest` and selecting the `svelte-ts` option.
+
 In both cases, a `svelte.config.js` with `vitePreprocess` will be added. Vite/SvelteKit will read from this config file.
 
 ### Other build tools
@@ -77,6 +79,14 @@ If you're using tools like Rollup or Webpack instead, install their respective S
 
 > [!NOTE] If you're starting a new project, we recommend using SvelteKit or Vite instead
 
+## tsconfig.json settings
+
+When using TypeScript, make sure your `tsconfig.json` is setup correctly.
+
+- Use a [`target`](https://www.typescriptlang.org/tsconfig/#target) of at least `ES2022`, or a `target` of at least `ES2015` alongside [`useDefineForClassFields`](https://www.typescriptlang.org/tsconfig/#useDefineForClassFields). This ensures that rune declarations on class fields are not messed with, which would break the Svelte compiler
+- Set [`verbatimModuleSyntax`](https://www.typescriptlang.org/tsconfig/#verbatimModuleSyntax) to `true` so that imports are left as-is
+- Set [`isolatedModules`](https://www.typescriptlang.org/tsconfig/#isolatedModules) to `true` so that each file is looked at in isolation. TypeScript has a few features which require cross-file analysis and compilation, which the Svelte compiler and tooling like Vite don't do. 
+
 ## Typing `$props`
 
 Type `$props` just like a regular object with certain properties.