feat: Add support for dark mode in dashboard (#7460)

- Add config for TailwindCSS
- Enable HMR
- Add a config in LocalStorage for Dark Mode

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

app/javascript/dashboard/components/Modal.vue

@@ -52,7 +52,8 @@ export default {
   },
   computed: {
     modalContainerClassName() {
-      let className = 'modal-container skip-context-menu';
+      let className =
+        'modal-container bg-white dark:bg-slate-800 skip-context-menu';
       if (this.fullWidth) {
         return `${className} modal-container--full-width`;
       }