docs(slide-toggle): fix typo for mat button (#19780)

Author: kirankumarsripati

src/components-examples/material/slide-toggle/slide-toggle-forms/slide-toggle-forms-example.html

@@ -21,5 +21,5 @@
 
   <p>Form Group Status: {{formGroup.status}}</p>
 
-  <button mat-rasied-button type="submit">Save Settings</button>
+  <button mat-raised-button type="submit">Save Settings</button>
 </form>