docs(readme): add usage in Sass / SCSS

README.md

@@ -44,7 +44,9 @@ npx grunt build
 
 ## Usage
 
-You can use the minified CSS file with a CDN service:
+You can use the minified CSS file with:
+
+1. A CDN service:
 
 - UNPKG: `https://unpkg.com/x-markdown-css@latest/dist/bundle.min.css`
 - jsDelivr: `https://fastly.jsdelivr.net/npm/x-markdown-css@latest/dist/bundle.min.css`
@@ -52,6 +54,22 @@ You can use the minified CSS file with a CDN service:
 
 > *ps. `bundle.css` without `.min` stands for unminified version.*
 
+2. A Sass / SCSS project
+
+First, install it with NPM ([PNPM](https://pnpm.io) or [Yarn](https://yarnpkg.com) also works):
+
+```sh
+npm i x-markdown-css@latest
+```
+
+Then, add it to your Sass / SCSS file (SCSS for example):
+
+```scss
+@import 'x-markdown-css';
+```
+
+> *ps. No path or file extention is required, just simply use `x-markdown-css` to import it.*
+
 ## Uses
 
 - [SCSS](https://sass-lang.com)