Stick to 'snake_case' for file reference

Mes0903 · Mes0903 · commit c33ff957adb7 · 2025-03-29T00:39:36.000+08:00
diff --git a/guide/book.toml b/guide/book.toml
@@ -6,5 +6,5 @@ title = "Learn Vulkan"
 
 [output.html]
 theme = "theme"
-additional-js = ["theme/lang-toggle.js"]
-additional-css = ["theme/lang-toggle.css"]
+additional-js = ["theme/lang_toggle.js"]
+additional-css = ["theme/lang_toggle.css"]
diff --git a/guide/translations/zh-TW/book.toml b/guide/translations/zh-TW/book.toml
@@ -6,5 +6,5 @@ title = "Learn Vulkan"
 
 [output.html]
 theme = "../theme"
-additional-js = ["../theme/lang-toggle.js"]
-additional-css = ["../theme/lang-toggle.css"]
+additional-js = ["../theme/lang_toggle.js"]
+additional-css = ["../theme/lang_toggle.css"]
