docs: update documentation for custom icons (#3655)

packages/foundations/docs/CustomIcons.md

@@ -2,70 +2,7 @@
 
 If you have custom icons and want to use them for [foundations](https://www.npmjs.com/package/@db-ui/foundations) and/or in [components](https://www.npmjs.com/package/@db-ui/components), you need to generate a **woff2** file.
 
-## Generate
-
-For this run:
-
-```shell
-npx @db-ui/gif --src ./my-path-to/icons --fontName my-name
-```
-
-We search for all `**/*.svg` files inside the `src` directory and create a new icon font with the provided name. You can preview all generated icons here: `./my-path-to/icons/fonts/all/index.html`.
-
-> **_NOTE:_** We use four different sizes for components (16, 20, 24, 32) to show more or less details. You can do the same by providing another file with a size suffix for example `icon_file_name_16.svg`.
-
-For more information run:
-
-```shell
-npx @db-ui/gif --help
-```
-
-## How to use
-
-In your app you need to include some of the generated files:
-
-```html
-./my-path-to/icons/fonts/my-name.woff2 ./my-path-to/icons/fonts/font-face.css
-```
-
-> **_NOTE:_** In case you put the files in a separate folder of your `public` directory be aware to adopt the path in your generated `font-face.css` file: `url("/{YOUR_FOLDER}}/my-name.woff2?t=1698750286189") format("woff2");`
-
-Now you can use your icons with your `font-family: my-name`, e.g.:
-
-```html
-<!--example.html-->
-<i class="my-name">icon_file_name</i>
-```
-
-### SCSS
-
-When using **scss** you can also use `@forward` to include the generated files:
-
-```scss
-@forward "public/font-face";
-```
-
-### data-icon
-
-If you like to use a custom icon in one of our components you can do it by overwriting the default font-family like this:
-
-```html
-<!--example.html-->
-<p class="icon-family-my-name" data-icon="icon_file_name">Test</p>
-
-<!-- or -->
-<p data-icon-family="my-name" data-icon="icon_file_name">Test</p>
-```
-
-### CSS
-
-You can overwrite custom-icons for our components with CSS as well:
-
-```css
-.db-button {
-	--db-icon-font-family: "my-name";
-}
-```
+Check out the `icon-font-tools` [documentation](https://github.com/db-ui/icon-font-tools/blob/feat-cosmiconfig/docs/GenerateIconFonts.md) to generate a **woff2** file.
 
 ## Foundation Developer