docs(tabs): add "Container type (full width)" example

Author: metonym

docs/src/pages/components/Tabs.svx

@@ -104,7 +104,7 @@ Use the `icon` prop to render an icon next to the tab label. The icon is rendere
 
 ## Container type
 
-Use the container type for a more prominent tab interface.
+Use the container type for a more prominent tab interface. By default, container types have an auto-width.
 
 <Tabs type="container">
   <Tab label="Tab label 1" />
@@ -117,6 +117,21 @@ Use the container type for a more prominent tab interface.
   </svelte:fragment>
 </Tabs>
 
+## Container type (full width)
+
+Combine `type="container"` with `fullWidth` for container tabs that evenly span the full width of the container.
+
+<Tabs type="container" fullWidth>
+  <Tab label="Tab label 1" />
+  <Tab label="Tab label 2" />
+  <Tab label="Tab label 3" />
+  <svelte:fragment slot="content">
+    <TabContent>Content 1</TabContent>
+    <TabContent>Content 2</TabContent>
+    <TabContent>Content 3</TabContent>
+  </svelte:fragment>
+</Tabs>
+
 ## Container type (disabled)
 
 Container type tabs with disabled states. Set `disabled` to `true` on individual tabs to prevent interaction.