Add v5.3.3 docs (#39693)

docs/5.3/assets/js/color-modes.js

@@ -1,6 +1,6 @@
 /*!
  * Color mode toggler for Bootstrap's docs (https://getbootstrap.com/)
- * Copyright 2011-2023 The Bootstrap Authors
+ * Copyright 2011-2024 The Bootstrap Authors
  * Licensed under the Creative Commons Attribution 3.0 Unported License.
  */
 
@@ -20,8 +20,8 @@
   }
 
   const setTheme = theme => {
-    if (theme === 'auto' && window.matchMedia('(prefers-color-scheme: dark)').matches) {
-      document.documentElement.setAttribute('data-bs-theme', 'dark')
+    if (theme === 'auto') {
+      document.documentElement.setAttribute('data-bs-theme', (window.matchMedia('(prefers-color-scheme: dark)').matches ? 'dark' : 'light'))
     } else {
       document.documentElement.setAttribute('data-bs-theme', theme)
     }