docs: add note about coffeescript support (sveltejs#3063)

Author: bluwy

documentation/docs/90-additional-resources.md

@@ -19,7 +19,7 @@ We've written and published a few different SvelteKit sites as examples:
 
 ### Integrations
 
-[`svelte-preprocess`](https://github.com/sveltejs/svelte-preprocess) automatically transforms the code in your Svelte templates to provide support for TypeScript, PostCSS, scss/sass, Less, and many other technologies. The first step of setting it up is to add `svelte-preprocess` to your [`svelte.config.js`](#configuration). It is provided by the template if you're using TypeScript whereas JavaScript users will need to add it. After that, you will often only need to install the corresponding library such as `npm install -D sass`or `npm install -D less`. See the [`svelte-preprocess`](https://github.com/sveltejs/svelte-preprocess) docs for more details.
+[`svelte-preprocess`](https://github.com/sveltejs/svelte-preprocess) automatically transforms the code in your Svelte templates to provide support for TypeScript, PostCSS, scss/sass, Less, and many other technologies (except CoffeeScript which is [not supported](https://github.com/sveltejs/kit/issues/2920#issuecomment-996469815) by SvelteKit). The first step of setting it up is to add `svelte-preprocess` to your [`svelte.config.js`](#configuration). It is provided by the template if you're using TypeScript whereas JavaScript users will need to add it. After that, you will often only need to install the corresponding library such as `npm install -D sass` or `npm install -D less`. See the [`svelte-preprocess`](https://github.com/sveltejs/svelte-preprocess) docs for more details.
 
 [Svelte Adders](https://sveltesociety.dev/templates#adders) allow you to setup many different complex integrations like Tailwind, PostCSS, Firebase, GraphQL, mdsvex, and more with a single command. Please see [sveltesociety.dev](https://sveltesociety.dev/) for a full listing of templates, components, and tools available for use with Svelte and SvelteKit.