add divider before locale dropdown button.

src/theme/Navbar/Content/index.tsx

@@ -80,7 +80,12 @@ export default function NavbarContent(): JSX.Element {
 
       <div className={clsx('col col--5', styles.headerRight)}>
         <NavbarColorModeToggle />
-        {localeDropdown && <NavbarItem {...localeDropdown} />}
+        {localeDropdown && (
+          <>
+            <div className={styles.divider} />
+            <NavbarItem {...localeDropdown} />
+          </>
+        )}
       </div>
     </div>
   )

src/theme/Navbar/Content/styles.module.scss

@@ -71,6 +71,19 @@
   border-radius: 1rem;
 }
 
+.headerRight {
+  & > *:not(:last-child) {
+    margin-right: 34px;
+  }
+}
+
+.divider {
+  height: 11px;
+  width: 1px;
+
+  background-color: #d9d9d9; // TODO: use infima variables
+}
+
 @include utils.responsive('lg', 'down') {
   .root {
     padding: 0 var(--ifm-spacing-horizontal);