docs: include Vuetify SASS variables overriding (#288)

* Add documentation for Vuetify SAAS variable overriding

SAAS variable overriding was difficult to figure out how to configure using this module.  Provide some sample documentation for how to get it to work.

* Fix a typo in sass-variables.md

* Fix SASS typos

For some reason my tired brain was thinking Software as a Service, rather than SASS.  Replace them all.

* Swap comments for 'other options'

Use 'other options' verbiage instead of comment with ellipsis for clarity

* Move saas-variables.md to sass-modern-compiler.md

Per PR review, moving the contents of saas-variables.md (sic, sorry) to sass-modern-compiler.md as a sub-section.

* Delete docs/guide/saas-variables.md

* Add reference to SASS Modern Compiler in Server Side Rendering

Reference SASS Modern Compiler sub-section in Server Side Rendering doc

* Make SSR link to modern SASS vars relative

* Update SASS Modern Compiler doc title

* Make server side rendering reference to overriding sass variables more clear

* Change main.scss note to a tip for clarity

* Use backwards-compatible path syntax

* Use globals.scss for Vuetify override and clarify tip

* Update styles paths to be more standards compliant

* Add example link to component-level sass overrides

* Reword step 5 for clarity

* Update file header to SASS customization

* Update left-panel option name for clarity

* Update forgotten '@/' in nuxt config file

* Rename sass-modern-compiler to sass-customization and update link path

* Update broken link reference

* Add link to global sass variable index

* Make settings.scss code styled

* Change settings.scss to components.scss

docs/.vitepress/config.ts

@@ -191,8 +191,8 @@ export default withPwa(defineConfig({
         text: 'Date Support',
         link: '/guide/date',
       }, {
-        text: 'SASS Modern Compiler',
-        link: '/guide/sass-modern-compiler',
+        text: 'SASS Customization',
+        link: '/guide/sass-customization',
       }, {
         text: 'FAQ',
         link: '/guide/faq',

docs/guide/sass-customization.md

@@ -0,0 +1,70 @@
+# SASS Customization
+
+From version `0.17.0`, this module will configure Nuxt to use the new SASS modern compiler (`modern-compiler`). You don't need to change anything in your configuration to use it:
+- update `vite` version to `v5.4.0` or higher (if you're using Nuxt `3.12.4` or higher, you don't need to update `vite`)
+- replace your `sass` dependency with `sass-embedded`
+
+If the `sass-embedded` dependency is not installed, the module will configure the `modern` compiler for you. In case you get errors, enable the `disableModernSassCompiler` option in the module configuration to fall back to the `legacy` compiler.
+
+Check [Build Performance](https://vuetifyjs.com/en/features/sass-variables/#build-performance) in Vuetify docs for more details.
+
+## Overriding SASS Variables
+
+Vuetify allows for [overriding global and component-level SASS variables](https://vuetifyjs.com/en/features/sass-variables/).  Setting these up requires configuration that is slightly different from the Vuetify
+documentation while using this Nuxt module.
+
+1)  In your styles directory (for this example, we'll use `${srcDir}/assets/css`), create two files - `${srcDir}/assets/css/globals.scss` and `${srcDir}/assets/css/components.scss`
+
+2)  In the `globals.scss` file, we'll want to add
+```scss
+@use 'vuetify' with (
+    // Global Vuetify SASS variable overrides.  For example:
+    // $utilities: false,
+    // $reset: false,
+    // $color-pack: false,
+    // $body-font-family: sans-serif
+)
+```
+
+3)  In the `components.scss` file, we'll want to add
+```scss
+// $button-text-transform-override: capitalize;
+
+@forward 'vuetify/settings' with (
+    // Component Vuetify SASS variable overrides.  See https://vuetifyjs.com/en/features/sass-variables/#variable-api
+
+    // For example -- overriding button font capitalization (as seen at the bottom of the v-btn guide here https://vuetifyjs.com/en/api/v-btn/):
+    // $button-text-transform: $button-text-transform-override,
+);
+```
+
+4)  In your `nuxt.config.ts`, add a `css` entry to the `defineNuxtConfig` configuration object that points to `globals.scss` like so:
+```javascript
+export default defineNuxtConfig({
+  css: ['@/assets/css/globals.scss']
+  // other options
+})
+```
+
+> [!TIP]
+> The [css](https://nuxt.com/docs/getting-started/styling#the-css-property) property within your `defineNuxtConfig` will import all styles from the file that you specify (in our case, `globals.scss`) into all components for convenience. Any styles appended to the `globals.scss` file in addition to the Vuetify Global Variables override will also be imported into all of your components. If you would like more fine-grained control, consider using a different file for your non-Vuetify global styles, like a separate `main.scss` that you import on a component-by-component basis.
+
+5)  Again in your `nuxt.config.ts`, under the Vuetify module options, disable the Vuetify Styles import for components and instead import the `components.scss` override file:
+```javascript
+export default defineNuxtConfig({
+  css: ['@/assets/css/globals.scss'],
+  vuetify: {
+    moduleOptions: {
+      /* module specific options */
+      /* https://www.youtube.com/watch?v=aamWg1TuC3o */
+      disableVuetifyStyles: true,
+      styles: {
+        configFile: '@/assets/css/components.scss'
+      },
+    },
+  }
+  // other options
+})
+```
+
+You should now be able to override your [global Vuetify SASS variables](https://github.com/vuetifyjs/vuetify/blob/master/packages/vuetify/src/styles/settings/_variables.scss) as well as your [component-level Vuetify SASS variables](https://vuetifyjs.com/en/features/sass-variables/#variable-api).  For a full list of variables, check out [all of the imports in the index](https://github.com/vuetifyjs/vuetify/blob/master/packages/vuetify/src/styles/settings/_index.sass).

docs/guide/server-side-rendering.md

@@ -50,6 +50,8 @@ export default defineNuxtConfig({
 })
 ```
 
+For a more detailed example, see [Overriding SASS Variables](/guide/sass-customization.md#overriding-sass-variables).
+
 ## Vuetify Themes
 
 If you're using multiple Vuetify Themes with SSR enabled, Vuetify [useTheme](https://vuetifyjs.com/en/api/use-theme/) will not work since there is no way to know which theme to use in the server (the server will use the default theme).