Use native font stack (#417)

It ensures that the text is displayed in the font that the user is
most comfortable with, and it also reduces the size of the data
transferred.

Breaking change:

The Titillium web font has been replaced with native font stack.

Migration:

To keep the Titillium web font in your project, load the web font
and override the `--rui-font-family-base` custom property:

```
--rui-font-family-base: 'Titillium Web', helvetica, roboto, arial, sans-serif;
```

Author: adamkudrna

README.md

@@ -53,16 +53,7 @@ To install React UI in your app:
    npm install --save @react-ui-org/react-ui
    ```
 
-2. Load the Titillium Web font:
-
-   ```html
-   <link
-     href="https://fonts.googleapis.com/css2?family=Titillium+Web:wght@300;400;600;700&display=swap"
-     rel="stylesheet"
-   />
-   ```
-
-3. Load React UI CSS in your app:
+2. Load React UI CSS in your app:
 
    <!-- eslint-env browser -->
    <!-- eslint-disable import/no-unresolved -->
@@ -73,7 +64,7 @@ To install React UI in your app:
 
    <!-- eslint-env browser -->
 
-4. Import and use any of React UI components in your app:
+3. Import and use any of React UI components in your app:
 
    ```jsx
    import { Button } from '@react-ui-org/react-ui';

mkdocs.yml

@@ -29,8 +29,6 @@ theme:
   language: 'en'
   favicon: 'favicon.ico'
   custom_dir: 'src/docs/_overrides'
-  font:
-    text: 'Titillium Web'
   palette:
     - media: "(prefers-color-scheme: light)"
       scheme: default
@@ -135,6 +133,7 @@ nav:
           - TransferProps: 'helpers/transferProps/README.md'
   - Guides:
       - Customize:
+          - Font: 'docs/customize/font.md'
           - Theming:
               - Overview: 'docs/customize/theming/overview.md'
               - Forms: 'docs/customize/theming/forms.md'

package.json

@@ -56,7 +56,7 @@
     "precopy": "rm -rf dist && mkdir dist",
     "prepublishOnly": "npm run build",
     "start": "webpack --watch --mode=development",
-    "stylelint": "stylelint \"src/**/*.scss\" --config stylelint.config.js",
+    "stylelint": "stylelint \"src/**/*.{css,scss}\" \"!src/docs/_assets/generated/**\" --config stylelint.config.js",
     "test": "npm run jest"
   },
   "dependencies": {