docs: update README, links (#1509)

* docs: add note on using `optimizeImports` with `svelte-preprocess` (Closes #1500)

* docs: point link to SASS guide to v10 (#1489)

* docs: remove note on minimum Svelte version as it's been almost half a year since 3.48 was released

README.md

@@ -31,8 +31,6 @@ Other forms of documentation are auto-generated:
 
 Install `carbon-components-svelte` as a development dependency.
 
-A minimum Svelte version of 3.48.0 is required to use this library.
-
 ```sh
 # Yarn
 yarn add -D carbon-components-svelte
@@ -200,7 +198,7 @@ The preprocessor optimizes imports from the following packages:
 - [carbon-icons-svelte](https://github.com/carbon-design-system/carbon-icons-svelte)
 - [carbon-pictograms-svelte](https://github.com/carbon-design-system/carbon-pictograms-svelte)
 
-**Example**
+**Before & After**
 
 ```diff
 - import { Button } from "carbon-components-svelte";
@@ -222,6 +220,21 @@ export default {
 };
 ```
 
+`svelte-preprocess` should be invoked before any preprocessor from `carbon-preprocess-svelte`.
+
+```diff
+// svelte.config.js
++ import sveltePreprocess from "svelte-preprocess";
+import { optimizeImports } from "carbon-preprocess-svelte";
+
+export default {
+  preprocess: [
++   sveltePreprocess(),
+    optimizeImports()
+  ],
+};
+```
+
 ## Examples
 
 - [examples/rollup](examples/rollup/)