Update README

Resolves #3

Author: deathaxe

README.md

@@ -22,14 +22,106 @@ _Requires ST 4092 or higher._
 
 ## Usage
 
+### CSS
+
 This syntax is assigned to files which end with `tailwind.css` by default.
 
-You need to assign it to ordinary `*.css` files manually.
+To use it for ordinary `*.css` files manual assignment is needed.
 
 1. Click onto the syntax name in the status bar
 2. Navigate to the sub menu `Open all with current extension as...`
 3. Click on `Tailwind CSS`.
 
+To add highlighting for Tailwind @-rules to CSS in a way they are also supported within component syntaxes like [Svelte](https://packagecontrol.io/packages/Svelte) or [VueJS](https://packagecontrol.io/packages/Vue%20Syntax%20Highlight)...
+
+1. create a custom _Packages/User/CSS (Tailwind).sublime-syntax_
+2. paste the following content:
+
+   ```yml
+   %YAML 1.2
+   ---
+   name: CSS (Tailwind)
+   scope: source.css
+   version: 2
+   
+   extends:
+     - Packages/Tailwind CSS/Tailwind CSS.sublime-syntax
+   ```
+
+> [!WARNING]
+>
+> By assigning `source.css` main scope original PostCSS syntax is augmented.
+> 
+> 1. Augmenting syntax must be loaded after CSS in order for this trick to work.
+> 2. Only a single augmenting syntax may exist.
+> 3. Syntaxes, which extend core CSS to add their own rules can't be augmented this way.
+
+### PostCSS
+
+To add highlighting for Tailwind @-rules to PostCSS in a way they are also supported within component syntaxes like [Svelte](https://packagecontrol.io/packages/Svelte) or [VueJS](https://packagecontrol.io/packages/Vue%20Syntax%20Highlight)...
+
+1. create a custom _Packages/User/PostCSS (Tailwind).sublime-syntax_
+2. paste the following content:
+
+   ```yml
+   %YAML 1.2
+   ---
+   name: PostCSS (Tailwind)
+   scope: source.postcss
+   version: 2
+   
+   extends:
+     - Packages/Tailwind CSS/Tailwind CSS.sublime-syntax
+     # - ... maybe more additions
+     - Packages/PostCSS/PostCSS.sublime-syntax
+   ```
+
+> [!WARNING]
+>
+> By assigning `source.postcss` main scope original PostCSS syntax is augmented.
+> 
+> 1. Augmenting syntax must be loaded after PostCSS in order for this trick to work.
+> 2. Only a single augmenting syntax may exist.
+
+> [!NOTE]
+>
+> requires:
+> - [Sublime Text build 4152+](https://www.sublimetext.com/download)
+> - [PostCSS 3.0.0+](https://packagecontrol.io/packages/PostCSS)
+
+### SCSS
+
+To add highlighting for Tailwind @-rules to SCSS in a way they are also supported within component syntaxes like [Svelte](https://packagecontrol.io/packages/Svelte) or [VueJS](https://packagecontrol.io/packages/Vue%20Syntax%20Highlight)...
+
+1. create a custom _Packages/User/SCSS (Tailwind).sublime-syntax_
+2. paste the following content:
+
+   ```yml
+   %YAML 1.2
+   ---
+   name: SCSS (Tailwind)
+   scope: source.scss
+   version: 2
+   
+   extends:
+     - Packages/Tailwind CSS/Tailwind CSS.sublime-syntax
+     # - ... maybe more additions
+     - Packages/Sass/Syntaxes/SCSS.sublime-syntax
+   ```
+
+> [!WARNING]
+>
+> By assigning `source.scss` main scope original PostCSS syntax is augmented.
+> 
+> 1. Augmenting syntax must be loaded after PostCSS in order for this trick to work.
+> 2. Only a single augmenting syntax may exist.
+
+> [!NOTE]
+>
+> requires:
+> - [Sublime Text build 4152+](https://www.sublimetext.com/download)
+> - [Sass 4.0.0+](https://packagecontrol.io/packages/PostCSS)
+
 ## Related Extensions
 
 - [LSP-tailwindcss](https://github.com/sublimelsp/LSP-tailwindcss)