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/assets/scss/widgets/_conv-header.scss

@@ -59,11 +59,6 @@ $resolve-button-width: 8.25rem;
   flex-direction: row;
   flex-grow: 1;
   justify-content: flex-end;
-  margin-top: var(--space-small);
-
-  @include breakpoint(medium up) {
-    margin-top: 0;
-  }
 
   &.has-open-sidebar {
     justify-content: flex-end;