fix: add missing breakpoints (#1535)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Style**
* Introduced new CSS custom properties for additional responsive
breakpoints, enhancing layout adaptability across a wider range of
screen sizes.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

unraid-ui/src/styles/globals.css

@@ -35,6 +35,11 @@
 }
 
 @theme static {
+  /* Breakpoints */
+  --breakpoint-xs: 30rem;
+  --breakpoint-2xl: 100rem;
+  --breakpoint-3xl: 120rem;
+
   /* Container settings */
   --container-center: true;
   --container-padding: 2rem;